Distance Learning During the COVID-19 Pandemic: School Barometer Lithuania

. The COVID-19 pandemic unexpectedly changed the conditions of working and studying. It was mandatory in Lithuania to adhere to a personal isolation to protect yourself from the threatening spread of the virus in March–April 2020. Then schools, universities, vocational training centres, kindergartens and other educational institutions quickly adapted to the changed working conditions and switched to the provision of distance learning services. The aim of this article is to analyse the challenges faced by school communities in the transition to distance learning, and to provide good practice examples and insights for improvement. The survey was conducted using the School Barometer method. survey covers the following topics: information flow and information provision from policies, school authorities, schools, school leadership and teachers; reactions to the school lockdown caused by the COVID-19 crisis; perceived stress due to the COVID-19 crisis; students’ current situations at home; care and tutoring for students during the school lockdown by parents and school staff; digital teaching and learning, including demands, resources and practices; the role of school leadership and collaboration; the roles, motivations and competences of school staff; the demands, expectations and wishes of and for parents, students, school staff, school leadership, school authorities and the school support system.

survey covers the following topics: information flow and information provision from policies, school authorities, schools, school leadership and teachers; reactions to the school lockdown caused by the COVID-19 crisis; perceived stress due to the COVID-19 crisis; students' current situations at home; care and tutoring for students during the school lockdown by parents and school staff; digital teaching and learning, including demands, resources and practices; the role of school leadership and collaboration; the roles, motivations and competences of school staff; the demands, expectations and wishes of and for parents, students, school staff, school leadership, school authorities and the school support system.
In Lithuania, the School Barometer questionnaire was distributed April 2020, i.e. during the quarantine due to the COVID-19 pandemic. Members of school communities (N = 451) responded, and educators made up the biggest proportion (68%) among them. Other respondents also worked at school as administrative staff and social educators. Half of the educators in the survey worked in gymnasiums. These were mostly schools operating in the city (63%). It is also important to note that the respondents of the survey were the Lithuanian teachers who actively participated in the remote competence development webinars and consultations implemented by VMU Institute for Professional Development during the COVID-19 quarantine.

Challenges in implementing distance learning
The transition to distance learning has changed the style of teaching and the role of teacher. The respondents (70%) believe that the transition to distance learning posed serious challenges in school communities.
One of the challenges of distance learning was related to the peculiarities of students' age and competences. Younger students could only complete the assigned tasks with the help of their parents. The workload of social and special educators seeking to differentiate learning tasks for students with special needs increased. Sometimes students lacked independence, responsibility, learning competence. The low level of computer literacy and the inability to use electronic diaries of some students and their parents became apparent.
The work of educators has become more visible in society and 34% of educators believe that the teaching profession has become more valued in the COVID-19 situation. However, the other side of the coin, i.e. the increased workload of educators has also emerged. According to one of the teachers: "it was necessary to check the tasks performed by the students in practically every lesson, more time had to be devoted to preparation, therefore the working hours increased and fatigue appeared". It became more difficult to plan working hours. "Teachers' working day is not normal -parents want to make contact both in the evenings and on weekends." The educators think that there was a lack of clearly defined system of distance working.
The quarantine conditions due to COVID-19 and the sudden change in the nature of the work caused stress for some members of the school community (Lithuanian educators 21%). The respondents (26%) noted that students experience stress in a COVID-19 situation as well (Fig. 1). Other challenges of distance learning were related to online networking activities and computer tools.
According to the educators: "during the quarantine the learning platforms were overloaded even at night and during the day there were difficulties in connecting online", or "I had to use "hundreds of all kinds of platforms". Sometimes teachers and students used old computer equipment because there were not enough funds in some areas to provide each teacher with a new computer. In many cases the educators had to use their personal computers, telephones and electricity. The teachers also raise a question how these costs will be reimbursed.
Finally, challenges arose due to the lack of digital learning content and methods. The teachers pointed out that there is a lack of digital learning tools and educators have to spend a lot of time "digitizing" tasks. They also faced a lack of methodologies for maintaining or enhancing students' motivation, assessing and practical teaching while working online.
When discussing the teacher competence development, the respondents expressed the need to improve IT competencies. They expressed a desire to have more online in-service training programs.
In order to address the encountered challenges, the participants of the survey usually turned to the school head, parents and searched for other creative solutions.

Parents' support in distance education and expectations regarding it
The respondents (60%) noted that they had received support from parents of students under quarantine and distance learning conditions.
The educators shared specific examples of parental assistance, such as donating tablets and computers to classmates, providing support with other technical means, offering transportation if there was a need to visit students. Parents were involved in planning "outdoor classes", creating "chat rooms" on social networks, filming tasks performed by students, and consulting with each other on how to use online platforms. In the context of distance learning, parents played an important role in creating appropriate conditions for students to participate in lessons without hindrance. In most cases, parents assumed responsibility for motivating children to participate in distance learning lessons, controlled the teaching process, and analysed the recommendations provided by teachers. During distance learning, the workload of independent learning for students increased significantly, therefore parents were actively involved in finding ways to reduce this workload for their children. More active parents collaborated to discuss a schedule for virtual lessons. The educators noted that in many cases, parents responded when teachers wanted to contact them to discuss learning issues. During the quarantine, parents actively cooperated with teachers solving encountered problems, trusted the competence of teachers and school administration, actively participated in distance learning (webinars) organized for parents.
Parents often provided emotional reinforcement in support of a new form of learning. However, the respondents (35%) noted that parents' expectations of the school in the face of COVID-19 were too high.
Some of the parents' expectations were related to the organization of distance learning and teaching/learning methods. Parents required teachers to keep their children online without breaks (despite hygiene requirements), to deliver more distance learning lessons and to explain more. Parents were asking fewer self-directed assignments, more video lessons, more teacher-student communication and individual counselling services. Some parents wanted teachers to provide teaching services after their working hours.
Parents expressed expectations regarding the safety of children in the online space to prevent bullying online. Some parents wanted teachers to provide computer equipment, food rations, and education support professionals to ensure full support to the student.
In fact, some parents expressed a wish to return their children to school as soon as possible for various reasons.

Preparation of school communities for the implementation of distance learning
Cooperation in the pedagogical community facilitated finding solutions to the challenges of distance learning. The pedagogues (74%) noticed that a high level of mutual assistance prevails in the school pedagogical community, teachers are motivated to implement distance learning in schooling practice (Fig. 2). The educators (60%) together with their colleagues prepared learning material for distance learning in the COVID-19 situation (Fig. 4). The respondents (85%) mentioned that there is an ongoing discussion in the school pedagogical community in order to develop an appropriate strategy for the implementation of distance learning activities (Fig. 3).
Active learning and cooperation in the pedagogical community have become especially relevant also due to the lack of experience of the respondents (18%) in applying different forms of distance learning in practice. The educators (20%) noted that it is not easy for them to develop distance learning processes.
Positive reactions of teachers in the transition to distance learning are primarily related to the fact that distance learning is interesting for teachers. In addition, it is a great opportunity to improve professional competences (new IT platforms, new working methods, interdisciplinary integration, etc.) and to strengthen cooperation in school community (strategy of distance working, creation of digital content). The teachers actively registered for distance learning webinars.
Some educators saw work at home as a great opportunity to combine professional activities with family responsibilities. Working from home saved time that educators often waste in traffic jams or during the gaps between their lessons. Some respondents saw the potential benefits of distance learning for students. Students are expected to become more independent, to value teachers and the school more.
The teachers noticed that after switching to distance learning, some unmotivated students revealed their strengths. The application of distance learning technologies more often revealed the creativity of students. The respondents (92%) noticed that by applying distance learning methodologies, students can receive individual teacher consultations, teachers check how students perform tasks at home.

N = 1.613-1.656 (Western Europe), N = 451 (Lithuania) (Stephan Gerhard Huber & Christoph Helm, Danguolė Bylaitė-Šalavėjienė)
In fact, there were also teachers in schools that lacked mutual understanding, felt too much control from the school administration, the burden of extra work and pointless paperwork. The respondents (13%) noticed that while studying online students sometimes felt being on holiday. The teachers used a variety of methods to communicate with students remotely, usually employing distance learning platforms. Over 50% of the respondents agreed that the technical capacities in the school are sufficient for web-based formats (Fig. 5).

Proven distance learning tools and methods
The respondents enlisted the proven means of distance learning. Padlet platform was mentioned as suitable for working in kindergarten. The following platforms were also mentioned by the respondents: Moodle, Microsoft Teams, Wordwall, Ziteboard, Google meet, Tamo AUT,634;CH,174;LT,451 (Stephan Gerhard Huber & Christoph Helm, Most of the time the teachers used a number of communication and distance learning tools, such as: "I submit the task in the Padlet program, send a link to the parents' e-mails or the Viber program. I communicate with parents and children via mobile phone and Viber app: messages, chats, video calls. Parents also took an active part in taking photos, filming their child's activities, completing tasks, sending them to teachers via the Viber program." Another teacher writes: "Eduka, Ema are very helpful in primary education. We use video lessons on the Zoom platform. I provide individual consultations by video calls". Another educator mentions: "Padlet app -for classes, messenger consultations and communication, Zoom for working with fellow educators". The respondent notes: "Gymnasium uses Moodle, Zoom, I use additional tools like Google classroom, etc." However, the respondents noticed that not all distance learning tools and methods have proved to be successful in working with high special needs students (blind children, the ones with complex disabilities, etc.), who are usually dealt with individually. Confusion for children and parents was caused by the abundance of distance learning tools used by teachers. The educators noted several cases of failure or difficulty in using certain remote learning platforms, such as Moodle, that had to be abandoned. It was difficult to use, the video room was constantly stuck, suitable only for senior students. The educators noticed that students did not like this platform. "The Moodle platform is too cumbersome, communication, sending and receiving tasks via TAMO -unnecessary system load." According to the educators, the Eduka class did not work properly: "It takes a lot of action to upload something. Not all textbooks are available and there are few tasks for senior classes." The respondents noticed that it was almost impossible to join the Eduka platform. The Eduka platform stalled for the first week. "Eduka and Edmodo allow uploading small files but do not provide for a preschool program." One of the teachers writes: "All the used electronic diaries got stuck". Educators' confidence has been lost in the Zoom platform: "Zoom hangs in the morning during school activities. Later it became clear that it was not safe to use this platform."

Why do we not reach all students remotely?
After the introduction of distance learning during the quarantine, the issue of access to education became especially relevant and was actively addressed by education, public authorities, business representatives, and non-governmental organizations. The educators (83%) noticed that they reached up to 90-100% of the students remotely. The remaining respondents reached fewer students.
Why is it not possible to reach all students remotely? At the beginning of the quarantine, some of the students did not have the technical means suitable for distance learning (computer, Internet, poor Internet connection in rural areas, etc.) Some students were unable to join due to special needs.
The educators also noted that a small number of parents do not have IT skills, parenting skills and are not willing to cooperate with teachers and help children in the learning process. The teachers have come to the attention of families at social risk who do not control the participation of children in distance learning processes.
The respondents noticed that after the transition to distance learning, the motivation of some students to learn decreased.
Another problem arose during the quarantine: some parents took their children to their grandparents. This change in living conditions disrupted the usual learning rhythm of some students. Also, in the absence of compulsory school attendance, some students started working during the quarantine.

Recommendations
Despite the fact that only a small number of Lithuanian schools had previously used distance learning practices on a regular basis, the school community was able to focus on and solve the challenges together during the COVID-19 pandemic.
To provide high-quality distance learning services to schools in the future, it is important to achieve the following long-term goals: to update distance learning platforms, to develop digital learning content and new teaching methods that ensure involvement of all students.
Great attention should also be paid to the organization of distance learning in order to reduce the workload of students, parents and teachers and to improve working conditions, including the provision of appropriate computer equipment and internet access.
It is equally important to ensure continuous training of the school community members by introducing distance learning tools.


DIGITAL READING ENGAGEMENT OF JUNIOR HIGH SCHOOL STUDENTS DURING THE ONLINE LEARNING

The pandemic of COVID-19 has forced the teachers and students to hold the teaching and learning remotely. All the process of learning was conducted online via various mobile applications. Students widely use smartphones as a medium to receive learning materials, join online classes, and study. However, it was questioned whether students are engaged with their reading materials when they have to read the texts on screen or digitally and learn from them. It is expected that the use of digital devices has influenced students' reading engagement, especially when the reading is to learn. This study aims to find out about the students' engagement in reading digital texts during online learning. The study collects the data from self-report questionnaires, interviews, and observation. The result shows that students do not experience behavioral and affective engagement as well as a negative response while they are reading the texts onscreen during online learning. Article History: Received: June, 2021 Revised: December, 2021 Published: December, 2021p 2018

INTRODUCTION
Teaching and learning have been changed on its trend as technology and information developed. Traditional teaching and learning mainly focus on classical and face-to-face meetings. However, nowadays, teaching and learning can be done remotely with the advanced development of technology. Technology has gone beyond the function of teaching aids but the media to help the teaching and learning process remotely, such as flipped learning, hybrid learning, and even online learning (McShane, 2004;Redmond, 2011).
The trend of online learning has been started since it has become more accessible. However, since the Covid-19 pandemic, online learning has been the foremost preference of almost all schools and institutions. Teachers should do the teaching from their place as well as the students. They need to study on their own at home. All materials like reading sources and assignments are mostly provided in digital files that students need to download or copy every day. This concept seems easy since it looks like the teachers only need to change the medium, but the teaching and learning remain the same.
However, some studies mentioned that the situation has an impact on students in many ways, such as unsustainable internet access, the ownership of electronic devices, or even the inability to cope with the teaching and learning process, which suddenly turned online from traditional teaching and learning (Agung & Surtikanti, 2020). The situations would, directly and indirectly, influence the students learning performance. They have to cope with the situations on their own. Even though they can always contact their teacher or friends, it is not as efficient as in non-online situations. Besides, Sharpe, Rhona & Benfield (2005) also discovered in their study that online learning also influences the students more emotionally, such as their concern about time spending and time management. Especially for the students in lower education level, such as Junior High School. They are not yet independent learners who are responsible for their doing. They still need guidance and reminder from the teachers. Meanwhile, not all parents are always available by their side during school hours at home.
Learning online cannot be separated from the reading activity online, which previously every text at schools was given on paper; the sudden changes influence the students. Even though the young generation nowadays has gotten used to and advanced in operating their smartphones to access a bunch of information online, it definitely cannot be generalized that they are also digital learners. Digital learning uses advanced technology devices and is a tool to acquire learning activities and materials in the teaching and learning process (Hockly, 2012). This statement has concerned how learners can engage with the online setting teaching and learning process, especially their reading activities digitally.
In addition, if the reading text is in a foreign language (Heppt et al., 2015). It is more cognitively challenging and usually requires language in which contextual cues for meaning are reduced (Chamot & O'Malley, 1996). Many learners read the text in their native language and in a foreign language, such as English, as many sources of knowledge are also written in different languages. Learners not only deal with the knowledge they want to get but also have to be concerned with language ability. It means that the reading activity is more purposeful and situated (Jetton & Alexander, 2000).
On the other hand, there are also some issues related to digital reading. Delgado & Salmerón (2021) found that reading on screen is not as effective as paper-based reading since it is more inattentive, especially when readers have to be faced with the task in a limited amount of time, so they tend to fail the whole text, which influences their information process. Fortunati & Vincent (2014) also stated that digital reading is not as exclusive as paper-based reading because digital interaction is mutual and does not involve a stronger emotional and sensorial experience. This makes reading on a digital platform not as comprehensible compared to paper-based reading (Halamish & Elbaz, 2020;Liu & Ko, 2019;Şimşek & Işıkoğlu Erdoğan, 2020).
Even though some studies also found that more comprehension and engagement in digital reading appears when students are well skilled and have a better experience (Burin et al., 2020;Delgado & Salmerón, 2021;Minguela et al., 2015). Learners who have been trained to read onscreen frequently navigate their online reading better. More skilled readers are more flexible in approaching texts, which influences their deep reading comprehension. However, the unexpected current situation of online learning has shown that the preparation for students is less or possibly none.
Based on the previous study, digital reading has been explored a lot, especially how to improve their reading competence at a younger level of education (Halamish & Elbaz, 2020;Liu & Ko, 2019;Turner et al., 2020;Zhang, 2013). However, not yet much discus about the students' reading engagement on digital texts, which previously mentioned that there are issues related to it. Therefore, this study aims to explore more on the students' reading engagement on digital reading texts during online learning.

RESEARCH METHOD Research Design
This study is qualitative research because it looks for deep comprehension and detailed descriptions about subjects as well as using multiple data collection techniques (Ary et al., 2010). The research will be conducted to find out the digital reading engagement by EFL learners in reading digital academic text during online learning. Qualitative research was used in this research to emphasize the complex constituents of reading engagement. The research aims to explore EFL students' reading engagement.

Population and Sample
The participants of this study were a class of 32 students of Islamic Junior High School in Indonesia. They are first-grade students, and all of them are females. They have been doing online learning because of the pandemic since they started becoming Junior High School students. They were observed during having reading classroom online and were asked to do self-report questionnaires. The interview was conducted only on four students who agreed to be interviewed.

Instruments
To collect the data for this study, the researcher observes classroom interaction through video meetings and group chats. During the online learning via video meeting, the students will be asked to read texts given by the teacher in the group chat. They read and understood the text during the online classes conducted in four meetings for two weeks. Then, an unstructured self-report questionnaire was given to the students after the learning process had over. The self-report questionnaire was given to the students to determine their engagement toward the reading (Chapman, 2003). To get deeper information about the students' engagement as well as the students' perception during digital reading texts, some students who wanted to give their statements were interviewed. There were only four students who agreed to be interviewed which most of them have better English abilities than their classmates. The interview was conducted in Indonesian.

Data Analysis
The data, which has been collected verbally and non-verbally from the students through the result of the observation, self-report questionnaire, and the interview, was organized, coded and reduced, and interpreted with the related theories.

RESEARCH FINDINGS AND DISCUSSION Research Findings
Based on the data collected, the finding of the students reading engagement which are their behavioral and affective engagement were gathered from the result of the questionnaire and observation. Several questions were pointed out in the questionnaire related to behavioral engagement and affective engagement. The behavioral engagement questions were related to their response during the online class via video meeting when the teacher asked them to read a text in the link given. The questions related to the learners' emotional reactions and their attention to the reading, such as their preferred activities, their desire about the knowledge given, their feeling and excitement about the process of reading on the screen to learn. Based on the result of the students' self-report questionnaire, it was discovered that on the behavior engagement, students fulfilled the aspect of conduct during the lesson and their interest toward the task even though from the statement in the report, they did not show lots of positive results. In the aspect of learners' conduct during the reading activity in the online class, they experienced false expectations that they thought reading was the same whether online or on paper. In fact, it is more problematic as the next aspect they also experienced was the technical problems, such as internet connection and digital distractions. In addition, less advanced use of devices also influenced their reading engagement. Not all students have more than one devices to support their learning. Most of them used their smartphones to join the online class as well as read the materials. They did not get used to using multiple sites for their learning since their previous learning was mostly conducted asynchronously through What's App group chat. Therefore, it is not convenient for them to read and join the class on one narrow device. Only two students used laptops for the online class, which provides them better reading and learning experience.
Students' interest in the text also shows that they were less enthusiastic toward the reading lesson during the online class. Whether they have understood or they were actually had no idea what is going on is unclear. They participated less during the lesson and mostly listened to the teacher of the outstanding students. They tended to rely on the teacher's explanation and wait for her to give them further understanding. It shows that they depended on the teacher to solve their problem instead of finding out by themselves or collaborating with their friends. They mentioned that they could not work together with their friends. In the classroom, they would likely discuss with their friends about the reading as simple as asking the meaning of the words, but when they are reading on the screen there is little chance to have an interactive experience.
The next result of the questionnaire on their affective engagement also showed negative results. There were two aspects noted from the self-report questionnaire; those are learners' feelings and values during the reading lesson online. Learners' felt less interested since they experienced technical problems, they also felt anxious when the teacher asked them questions since they did not understand the text well. They mentioned that they do not get what they read. It is confusing to read on a narrow screen, and they just go up and down the screen. When the teacher asked them questions, they skimmed the text to get the answer rather than understand the texts, making them read shallowly. The result of the self-report questionnaire in Table 1 also shows that the students mostly appear to accept the onscreen reading process negatively. The observation result also supports the same way especially focusing on the behavioral engagement and affective is not observable superficially. Based on the result of the observation, the students were expected to show their behavioral engagement through their activeness in the discussion, such as asking questions, giving comments, or responding teacher's questions. However, this study found that the students did not show their activeness during the reading, especially at the first meeting. They looked confused and kept scrolling up and down their screens on the screen. Some students also did not read enough because they needed to wait for the page to load.
In further data collection, which is the interview, it was found that the students just read the text thoroughly. They did not aim to understand the whole text but to answer the teacher's questions and to complete the assignments. When they faced problems such as does not understand the contexts, they did not bother to ask for friends, clarify to the teacher or browse online by themselves. When they met new vocabularies too, they skipped it and ignored it, especially if they felt it was unimportant. However, one student also copied the text to Google Translate because she wanted to know what she read.
In addition, students also could not value their reading and their learning because, during the reading activity, the teacher mostly focused on the active students, which were the outstanding students. The other students were noted to be present without fully making sure that they were engaged with the reading lesson. When they failed to finish or solve the tasks given by the teacher, they felt unsuccessful. They felt that they could not make better changes in their learning because they did not get enough during the lesson.
In sum, the result of the observation, questionnaire, and interview is that the students lacked belonging while reading on screen, could not make conceptual the thinking process, had less sharing experience in their reading, and did not perform preference to customize their personalization. They also fail to tackle the problem or apply certain strategies to improve their engagement with the texts they read.

Discussion
The learners' behavioral engagement cannot be portrayed in their involvement, responses, and reaction toward the reading activity in the online classroom. Most of the students did not show their activeness during reading in the online classroom by asking questions, giving comments, or feedback to their friends. Chapman (2003) mentioned that asking relevant questions during the teaching and learning process shows students' behavioral engagement in their learning which failed to prove in this study. Even though positive actions also appeared, only on some students who have better English competence than their other classmates. The use of technology in reading issues disengagement in the teaching and learning process, but it can increase engagement as it is used effectively (Heflin et al., 2017). The students also face distraction during the implementation, which is mostly related to technology use, which affects their excitement in learning. It is supported by Heflin et al., (2017) that the mobile device is associated with the students' positive response to learning even though it does not always support their critical thinking on their writing significantly, which is relevant to the current study. One gadget is used by the students to join the video meeting, group chat, and read the materials is multimedia, which made the students be able to multitask. As a result, they cannot fully focus on their reading compared to books that do not have such features.
Regarding effective engagement, the students show less enthusiasm during the reading on screen and when the teacher asks them about their reading. Chapman (2003) mentioned that affective engagement could be seen through learners' positive attitudes and intense interest in the learning process. They mentioned in the interview that they are mainly not confident in their English ability and do not know much English vocabulary. Therefore, they used online translation or just simply ignored the difficult words until being explained. Moreover, they only attach to the words near the pictures. They also tend to avoid reading long paragraphs. It means that while providing students reading on screen, interesting activities should be involved to make them engage with their reading and understand the reading content better, which is the responsibility of the teacher. In her study, Cho & Castañeda (2019) also mentioned that fun activities using their mobile phone, which is less serious and more game-like activity, can enhance learners' effective engagement. Another way is suggested by Hamsia et al. (2020) that cognitive, contextual, and motivational factors during online learning can also be developed through practicing self-regulated learning, which promotes their independence learning on their own.
Even though negative affective appeared at the beginning of the implementation, such as self-doubting about their ability, less enthusiasm, and the lack of advance of their devices as the teacher and the classmates does not discourage them about the problem, the students have stopped worrying about it and getting used with the technical problems as the time goes by. Baumeister et al. (2001)also mentioned that it is not a quick process to change the negative affective because it has been created in their mind from the very beginning, but it does not mean that it could not be changed in the process.
The finding confirmed that the use of digital texts to teach reading during distance learning could influence learners' enthusiasm, excitement, and engagement in their reading as well as their learning (Hutchison, 2019;Litterio, 2018;Mina, 2019). The finding indicates that students perceived a negative impact on their learning such as being less motivated, less passionate, less curious, and less active to do the tasks. Therefore, the teachers need direction on how to read digital texts, such as by applying certain digital reading strategies. Even though the habituation made the obstacles at ease, guidance and practices from the teacher about how to read texts digitally should be given. They need to be introduced to the features of digital texts that paper-based texts do not have, such as hyperlinks, search/find buttons, and instant word translation. Even though teachers and students are separated during online learning, teachers' value and assistance are needed as important as normal classroom situations, especially when they are not yet ready for sudden learning changes (Situmorang et al., 2020). By the consistent process and assistance from the teachers in applying reading texts on screen, it is believed that the negative impact and reduce gradually.

CONCLUSION
The unexpected changes in teaching and learning online can influence learners' engagement in reading digitally. Reading engagement can be improved by guiding learners to apply specific digital reading strategies to help them with their reading understanding and encouraging students' reading involvement during the reading class. It has been proven in the current study that it promotes students' behavioral and affective engagement. Even though negative response appears dominantly in this study towards students' digital reading engagement, this study also has shown that innovative media and involvement used during online reading class can help learners build engagement in their reading as well as build better collaboration with their classmates. Students should be supported more during distance learning as they face more than just external distractions, influencing their digital reading motivation and excitement. Those will affect their learning engagement in the classroom, which can lead to difficulties in achieving learning success.


Breaking Bricks: A Hands-On Model of Enzyme Kinetics and Inhibition

Enzyme kinetics and the impacts of inhibitors on the enzyme’s maximal velocity and ability to bind substrates are important topics in cell biology and biochemistry. However, these topics can be difficult for students to grasp when instructed using a traditional lecture format. Teaching biological concepts using physical models has been shown to improve to student comprehension and engagement with the topic. We have developed a pre-lab activity that uses plastic building bricks and student “enzymes” to expose students to these concepts prior to conducting enzyme assays at the bench. Small groups of students take turns acting as an enzyme that catalyzes a hydrolysis reaction with increasing substrate concentration in the presence and absence of a competitive inhibitor. Students graph brick breaking rate data and make observations about the effect of changing parameters on key metrics. We conclude the activity with a class discussion on their observations. According to survey data, our students show an increase in the ability to answer conceptual and graphical questions correctly after completing the activity and corresponding material. Moreover, the majority of students thought that the activity was moderately or greatly helpful at increasing their understanding of key concepts. This kinesthetic active learning approach provides an engaging and fun way to introduce students to modeling enzyme kinetics and is adaptable to any class or laboratory setting. Citation: Darling LEO, Goss JW, Roden JA. 2021. Breaking bricks: A hands-on model of enzyme kinetics and inhibition. CourseSource. https://doi.org/10.24918/cs.2021.16 Editor: Leocadia Paliulis, Bucknell University Received: 7/20/2020; Accepted: 12/22/2020; Published: 4/8/2021 Copyright: © 2021 Darling, Goss, and Roden. The authors affirm that they either own the copyright to or have received written permission to use the text, figures, tables, artwork, abstract, summaries, and supporting materials. This is an open-access article distributed under the Creative Commons Attribution-NonCommercial 4.0 International License. The authors retain ownership of the copyright to their article, but allow anyone to download, reuse, reprint, modify, distribute, and/or copy the article, as long as the original authors and source are cited and the intended use is not for commercial purposes. Conflict of Interest and Funding Statement: None of the authors has a financial, personal, or professional conflict of interest related to this work. Funding for supplies to develop the lesson was provided by a Wellesley College Educational Research and Development grant to J.A.R. Supporting Materials: Supporting Files S1. Breaking Bricks – Student Activity Handout; S2. Breaking Bricks – Introductory Slides for Enzyme Kinetics Activity; S3. Breaking Bricks – Enzyme Kinetics Activity Datasheet; S4. Breaking Bricks – Discussion Questions; S5. Breaking Bricks – Pre-Assessment; and S6. Breaking Bricks – Post-Assessment. *Correspondence to: jroden@wellesley.edu, Department of Biological Sciences, 106 Central Street, Wellesley MA CourseSource | www.coursesource.org 2021 | Volume 08 1 Lesson

INTRODUCTION
Enzyme kinetics and inhibition are fundamental topics in cell biology and biochemistry. Many textbooks used for these courses include a discussion of the structure of enzymes and their active and allosteric sites, the effect of increasing substrate concentration on the rate of reaction, and the definitions of the theoretical maximal velocity of the reaction (V max ) and the Michaelis constant (K m ), the substrate concentration at which half the active sites of the enzyme are filled (1). The mathematical model of enzyme kinetics developed by Leonor Michaelis and Maud Menten and the Lineweaver-Burk (double reciprocal) plot enable estimation and calculation, respectively, of V max and K m for an enzyme-catalyzed reaction. In addition to their relevance for biochemistry, the analytical methods used to interpret simple enzyme kinetics data are more broadly relevant. The American Association for the Advancement of Science's Vision and Change report describes the ability to use quantitative reasoning and mathematical modeling on biological data as one of the core competencies that should be included in undergraduate biology education (2). However, many students struggle to understand these key concepts. A survey of undergraduate biochemistry students from several different institutions demonstrated that some respondents still held misconceptions about characteristics of substrate binding to the active site of an enzyme even after they had been taught the material (3). Additionally, through several semi-structured interviews, it was clear that students had differing levels of understanding of the action of inhibitors on an enzyme reaction scheme (4). Finally, students' ability to describe the effect of non-competitive and uncompetitive inhibitors was less nuanced than their descriptions of competitive inhibition (5). Thus, incorporating multiple methods to expose, engage, and guide students through these concepts and analyses would likely improve student understanding.
Many studies suggest that teaching with active learning, which includes both activities and group discussion as opposed to passive listening to an expert, improves student outcomes. A meta-analysis comparing student examination scores throughout science, mathematics, engineering, and technology courses demonstrates that student performance is higher in courses that incorporate active learning (6). In addition, students in an introductory biology course that included active learning activities reported significantly more learning, increased interest in the course material, and more stimulation in the classroom than a cohort taught by the same instructor in a lecture-based format (7). While active learning can take many forms, incorporating physical models of biological phenomena can have marked effects on student learning. For example, female undergraduates who spent a discussion section manipulating physical models showed significant improvement in understanding both by quiz score and by student assessment of their own learning (8). In addition, male and female students in a cell and molecular biology class showed significantly higher learning gains on concepts that were taught using model-based activities than concepts taught without models when tested using a Central Dogma Concept Inventory (9). Finally, over 80% of the students that used a strategy of Process-Oriented Guided Inquiry Learning (POGIL) to build knowledge in a biochemistry course thought that these POGIL activities were helpful to their learning and recommended them for use in future versions of the course (10). Thus, incorporating student-centered, constructive activities into biology and biochemistry learning has many benefits for students.
We formerly began our laboratory study of enzyme kinetics with short presentation-based lectures at the start of each lab session, which included examples and discussion questions for students. However, this strategy did not engage students, who remained confused about key measurements and how to graphically represent them until they collected and began to analyze their own experimental data. We decided to develop a more student-centered lesson that incorporated active learning. Several different physical representations and models of enzyme kinetics have been developed previously. In one activity, students create enzymes out of modeling clay and manipulate them to represent shape changes during reactions (11). Two activities simulate enzymatic transport by having students transfer marbles between containers (12) or remove beans from a bag (13). Finally, other activities ask students to add pennies into a tube from a mixture including other coins as "inhibitors" (14) or unscrew nuts from bolts (15) to model Michaelis-Menten kinetics. However, none of these hands-on models of enzyme kinetics directly model a hydrolysis reaction, and many are directed at non-major or chemistry major student populations.
In our cell biology course, the attached laboratory uses the enzyme beta-galactosidase as a model and examines the effects of inhibitors on enzyme kinetics. Beta-galactosidase is part of the Escherichia coli lac operon, a model of gene regulation first described by François Jacob and Jacques Monod (16). Betagalactosidase catalyzes the cleavage of the disaccharide lactose into two monosaccharides, galactose and glucose, as well as a transgalactosylase reaction converting lactose to allolactose (17). The crystal structure of beta-galactosidase bound to several different inhibitors, including the competitive inhibitor isopropyl β-D-1-thiogalactopyranoside (IPTG), has been solved, and the Michaelis constant (K m ) of the enzyme in the presence of these inhibitors has been measured (18). Over the course of several weeks, our students follow a series of protocols to purify betagalactosidase from E. coli and spectroscopically measure the rate of enzyme-catalyzed cleavage of a substrate. They then select a potential inhibitor, predict its effect on the reaction, design an experiment, and observe and analyze their findings.
In this lesson, we describe a hands-on model that introduces key topics related to kinetics of a hydrolysis reaction similar to that catalyzed by beta-galactosidase, along with the effects of competitive and noncompetitive inhibitors on the reaction. We have created a physical model of this enzyme catalyzed reaction using students as enzymes and a familiar object as the substrate (plastic building bricks such as LEGO TM ). As part of the lesson, we incorporated opportunities for groups of students to create simple graphs with this model data and thought questions to help students discuss the successes and limitations of this model.

Intended Audience
This lesson is appropriate for an intermediate undergraduate cell/molecular biology or biochemistry course that discusses the topic of enzyme kinetics, particularly in the context of an enzyme that catalyzes a hydrolysis reaction. The lesson has been successfully implemented in a 50-60 student intermediate Cell Biology course during the 12-person attached laboratory sections at a small, selective, women's liberal arts college. Our course primarily enrolls biological sciences, biochemistry, and neuroscience majors who are fulfilling a major requirement, although a small subset of non-major pre-health students enroll in the course due to interest. Students are required to have 3 Breaking Bricks: A Hands-On Model of Enzyme Kinetics and Inhibition taken 2 semesters of college chemistry prior to enrolling in the course. According to our student survey data, the majority of the students have not yet taken or are currently co-enrolled in a biochemistry course, another course where enzyme kinetics is covered in our curriculum.

Required Learning Time
This lesson can be completed in an hour to 75 minutes as written, though modifications to add or eliminate testing and discussion of various potential inhibitors could shorten or extend this time. In our course, this lesson was spread over parts of two lab sessions. In the first 45-minute session, pairs or small groups of students used the hands-on model to collect and graph data in the presence and absence of inhibitors. After completing the activity and before the next lab session, each student independently answered thought questions. At the beginning of the next laboratory session (one week later), the instructor facilitated a discussion of the activity, what students learned, and extensions and drawbacks of the model for 20-30 minutes prior to beginning wet-bench enzyme kinetic experiments with a purified enzyme and varying substrate concentrations.

Prerequisite Student Knowledge
Prior to completing this lesson, students should familiarize themselves with the basic concepts of enzyme kinetics and inhibition, which are typically described in many cell biology and biochemistry textbooks, such as Molecular Biology of the Cell (1). In our course, relevant information about the Michaelis-Menten and Lineweaver-Burk plots, definitions of the Michaelis constant (K m ) and maximum velocity (V max ) of an enzymecatalyzed reaction, the effects of inhibitors on these values are provided in the electronic lab manual. Students are asked to read the lab manual prior to the lab session where the lesson is taught. Key concepts in enzyme kinetics are also discussed in the lecture portion of this course at this point in the semester.
Additionally, students should be comfortable taking numerical data and creating a simple scatterplot and adding a trendline using a graphing program.

Prerequisite Teacher Knowledge
Instructors should have a good understanding of the key enzyme kinetics terms and concepts described for students above. In addition, they should be able to take numerical data (substrate concentration and product formation rate) and create a scatter plot and be able to troubleshoot student graphing issues.

Active Learning
In this lesson, students use a hands-on model for enzyme kinetics as well as collecting and graphing their own data. This strategy encourages students to work together to simulate an enzyme-catalyzed reaction, analyze the data, and compare what they observe to what they have learned about the function and structure of real enzymes. Cooperative, constructivist-based activities that are open ended, require interpretation, and have answers that are not directly found in a textbook were proposed as strategies that are effective to help students build knowledge in biology (19). Moreover, active learning using physical models of a biological concept has been shown to improve student scores on questions that test those concepts to a greater degree than concepts where other types of active learning, such as group problem solving or clicker questions, are used (9). These types of activities can be included in Process-Oriented Guided Inquiry Learning (POGIL), in which small groups of students use active learning activities led by students and facilitated by the instructor to develop their own understanding, explore models, use discipline-specific knowledge, and develop important skills (20).

Assessment
Students in our course have multiple opportunities to demonstrate their understanding of enzyme kinetics and inhibition. During the activity, students are prompted to answer questions on the activity worksheet and discuss answers with their lab partners. At the end of the activity, students complete wrap-up questions, which are discussed as a class. Prior to the next week, students answer pre-lab discussion questions focused on the concepts introduced in the lesson. In our course, after completing this activity students conduct an experiment using beta-galactosidase that they have purified from E. coli to catalyze the hydrolysis of a substrate in the presence and absence of a potential inhibitor. Laboratory assignments ask students to examine and graph the data and use these measurements to discuss whether a particular chemical is an inhibitor, and if so, what type. We also assess student learning of these concepts on summative exams and problem sets in the lecture portion of the course.
In designing the Breaking Bricks activity and its corresponding assessments, we focused on addressing two core concepts from Vision and Change (2). First, our activity and corresponding laboratory experiments expose students to the idea that protein structure defines its function. Second, we connect the biological process of enzyme-catalyzed hydrolysis into a larger framework of chemical transformation pathways that are governed by the laws of thermodynamics. In addition, our activity allows our intermediate-level students to practice Vision and Change core competencies, such as applying quantitative analysis and mathematical reasoning to biological data, ability to use models to explain complex systems, and to communicate scientific information (2).
We evaluated whether this activity, in combination with other material discussed in the lecture portion of this course, was able to help students learn these concepts. We administered an anonymous survey to our most recent cohort of 37 students prior to the start of the laboratory period to evaluate students' baseline knowledge of enzyme kinetics and inhibition. One week after the lesson, we asked the same questions again. In the second survey, we also asked several attitudinal questions about the activity, modeled after questions used in a previously published assessment of an enzyme kinetics activity (12). The survey protocol was reviewed and was determined to be exempt from human subjects protections review by the Wellesley College IRB, under §46.101 b, Exemption 1.

Inclusive Teaching
This activity uses physical models and student participation, and instructors encourage all students to act out the part of enzymes. In addition, using familiar objects (plastic building bricks) as the substrates and a human action in place of the enzyme may make the concept of enzyme kinetics more relatable and approachable. This simulation is performed in small groups, where students can play several roles in 4 Breaking Bricks: A Hands-On Model of Enzyme Kinetics and Inhibition conducting the simulation (including timekeeper, data recorder, student "enzyme", or observer). Therefore, this activity could be modified to allow differently-abled students to participate depending on their needs by having the instructor and/or student group members discuss how all students can be involved prior to beginning the simulation. For example, in one of our classes, we had a visually impaired student who enjoyed being the "enzyme" because this kinesthetic activity doesn't require seeing the bricks.
This activity also provides multiple ways for students to answer questions about the material. When students complete the activity, they first answer questions in writing independently or in small groups, and then questions are discussed orally as a larger group. This technique allows all students to have the opportunity to participate. Structured discussion of individual student responses to the post-activity conceptual questions also allows students to teach each other.

LESSON PLAN
This lesson serves as a hands-on, conceptual model of enzyme kinetics in the presence and absence of an inhibitor. In the hands-on activity, students first define the enzyme, the substrate, and the products, then run the reaction without an inhibitor, create a simple graph of the results, and repeat the experiment again in the presence of the inhibitor. We conclude with a whole class discussion about the results of the activity, its benefits and limitations, and its connections to the experiments we will do in the lab.

Instructor preparation
Prior to the lesson, instructors should assemble the substrate building bricks into pairs, and sort them into containers holding about 60 substrates per container. We used 2 different colors for the substrates to model the glucose and galactose monosaccharides that make up the disaccharide lactose ( Figure  1). Instructors should glue together enough pairs of building bricks in a different, third color than the substrate (see Figure  1) to provide 15 inhibitors to each group of students. Through multiple trials, we determined that 15 inhibitor molecules added to each reaction approximates the human "enzyme's" K i (inhibitor constant, an inhibitor concentration where, under saturating substrate concentrations, half-maximal inhibition of the enzyme is reached). Creating inhibitor brick pairs in a different color of bricks than the substrate does not affect the outcome of the activity, but significantly shortens the cleanup and reassembly time required. Finally, instructors should make enough copies of the activity handout (Supporting File S1. Breaking Bricks -Student Activity Handout) for each student.

Student preparation
In advance of the lesson, students should read background information on enzyme kinetics, including effects of substrate concentration, definitions of K m and V max , and the effect of competitive and non-competitive inhibition on these reactions. In our course, we provided this information to students in our online laboratory manual, but it could also be disseminated as a textbook reading or a video mini-lecture depending on the course's needs and structure. Optionally, instructors can ask students to anonymously complete a pre-activity assessment (an example is provided as Supporting File S5. Breaking Bricks -Pre-Assessment) to measure the level of understanding of key concepts in enzyme kinetics prior to completing the activity.

In-Class Activities
Introducing and defining the system (5 minutes) The instructor begins this lesson by describing the setup and key concepts of the model (Supporting File S2. Breaking Bricks -Introductory Slides for Enzyme Kinetics Activity). Small groups of 2-3 students define the enzyme, substrate, product, and concept of saturation in this model of an enzyme-catalyzed reaction. These groups then take a container full of substrate to their workspace. Ideally, the classroom or laboratory space in which the lesson is taught should have enough surface area for each group of students to place, count, and sort the products and excess substrate, so lab benches or larger desks and tables are better for this activity than tablet chairs.
Enzyme kinetics in the absence of an inhibitor (10-15 minutes) The instructor should begin the activity with some instructions and ground rules for how to conduct the model experiment. We typically discuss the importance of keeping the motions of the "enzyme" consistent across volunteers, such as whether the student "enzyme's" eyes should be opened or closed, whether they should separate the bricks inside the container, and whether the products should be added back to the container. Each round of the activity starts with a designated number of substrate molecules (stacked pairs of plastic 2x2 bricks) in the container, mimicking different substrate concentrations. In our experience, trials with 5, 12, 20, 40, and 60 substrate molecules work well for five rounds total. In each round, one student will act as an "enzyme" to reach into the container and separate as many pairs of bricks into single bricks as they can in 30 seconds. The other member(s) of the group act(s) as the timekeeper. After the time is up, the group should count and record how many substrate molecules (pairs of bricks) were separated for that particular concentration. If the student "enzyme" separates all of the substrates in the container before the time is up, they should record the number of substrates with which they started. Instructors should also inform the group that if multiple students act as the "enzyme", it is important for each person to record their own data for each substrate concentration (each round), Breaking Bricks: A Hands-On Model of Enzyme Kinetics and Inhibition as each "enzyme" has their own V max . Students can refer to the handout (Supporting File S1. Breaking Bricks -Student Activity Handout) while they are completing this activity.
While students are performing the activity to separate bricks, the instructor can circulate through groups of students, observing how they are doing with the activity and asking about any questions that have come up. After all substrate concentrations have been tested, instructors should ask students to create a graphical representation of their data with a scatterplot in the form of a Michaelis-Menten plot, graphing substrate concentration on the x-axis and reaction rate (paired bricks separated per second) on the y-axis. This graph can be created either with a hand-drawn sketch or by inputting the data into a spreadsheet/graphing program (Supporting File S3. Breaking Bricks -Enzyme Kinetics Activity Datasheet).

Enzyme kinetics in the presence of a competitive inhibitor (10-15 minutes)
Once students have completed the first part of the activity, created a graph, and answered the corresponding thought questions, the instructor should pause the activity. At this point, the instructor should ask students, either in groups or as a class, about their observations on the effects of increased substrate on enzyme rate. Instructors should highlight and reinforce students' responses that demonstrate understanding that at low substrate concentrations, an increase in substrate leads to an increase in reaction rate, but at high substrate concentration, the reaction rate remains essentially the same. To transition to the next part of the activity, the instructor should then lead a brief discussion on competitive inhibition and its effect on an enzyme catalyzed reaction. One strategy we have used is to ask students what they might use as a competitive inhibitor or whether students think it is reasonable to use glued-together bricks as a representation for a competitive inhibitor.
The instructor will then distribute fifteen inhibitor brick pairs to each group of students. Students will repeat the enzyme cleavage simulation using the same five substrate concentrations, 30-second reaction time, and keep consistent the other motions of the reaction as described above but will add the fifteen inhibitor molecules to the container along with the substrate molecules. Each round will thus have a different substrate concentration (5,12,20,40, or 60 brick pairs) but a fixed inhibitor concentration (15 glued brick pairs). The instructor should remind students that they should keep their "enzyme" motions consistent with those from the uninhibited reaction. The instructor should provide two additional instructions for this part of the activity. If the inhibitor bricks are a different color or otherwise marked in some way, they should advise student "enzymes" to complete the reaction with their eyes closed. The instructor should also recommend that if the student "enzyme" is unable to pull apart the pair of bricks (whether it is an inhibitor molecule or just a stubbornly stuck substrate) that they place it back into the container.
At the conclusion of this portion of the simulation, students should then note their observations about how this simulation was similar or different to the reaction without inhibitor. Students should then graph the values as a new series on the same axes as the uninhibited enzyme (Supporting File S3. Breaking Bricks -Enzyme Kinetics Activity Datasheet). In small groups, they should examine these graphs and consider how the curves are similar to and different from each other, considering both the shape of the graphs and estimates of the K m and V max for each reaction. In group discussions, instructors can reinforce student observations describing a decrease in reaction rate of inhibited reactions at low substrate concentrations and minimal effect of the inhibitor on the reaction rate at high concentrations.
Non-competitive inhibition and other thought questions (5-10 minutes) After completion of the two different enzyme activity simulations, instructors should provide student groups with time to consider how they might adapt this model to show the effect of a non-competitive inhibitor. In this type of inhibition, the enzyme is able to bind to the substrate with similar affinity but the ability to stabilize the transition state and catalyze the reaction is reduced. Some examples our students proposed that model non-competitive inhibition in the breaking brick simulation are to run the experiment wearing a laboratory glove, or taping several fingers together. Note that if class time allows, students can incorporate their strategy to model noncompetitive inhibition by running enzyme brick simulation with their suggested modifications and identical substrate concentrations, but this will add 15-20 minutes to the total time of this activity. At the end of the activity, student groups should discuss extensions and caveats to using this model and note down any unanswered questions about enzyme kinetics (Supporting File S1. Breaking Bricks -Student Activity Handout).
To facilitate reuse of these materials by another group, students should reassemble the 60 substrate pairs and return them to their container. They should also sort out all of the inhibitor brick pairs used and return them to the instructor.

Wrap-Up and Assessment Activities
Concept-based questions (5-10 minutes, outside of class) There are many options to assess whether students understand the concepts modeled in this activity, including the effect of adding additional substrate on the rate of the reaction and the effect of a competitive inhibitor on the enzyme. Instructors in our course provide students with several conceptual questions to answer individually prior to the next course meeting (Supporting File S4. Breaking Bricks -Discussion Questions). At the beginning of the second class period, small groups of students hold a structured discussion about these conceptual questions modified from the ORID focused conversation method (21). Briefly, each student takes a turn to independently share their answers, then each student shares a reflection on differences between answers, and then the group synthesizes final answers. Optionally, if the pre-activity survey described above is used prior to the activity, instructors could ask students to complete a post-activity survey (for an example see Supporting File S6. Breaking Bricks -Post-Assessment).

Conceptual observations and thought questions (15-20 minutes)
As a way to draw connections between this activity and the action of a real enzyme, and as a formative assessment, instructors should moderate a group discussion of the final set of questions on the handout (Supporting File S1. Breaking Bricks -Student Activity Handout). Student responses to questions about strengths and weaknesses of the model often include both the benefit of a hands-on model for a complex reaction, 6 Breaking Bricks: A Hands-On Model of Enzyme Kinetics and Inhibition and the caveat that our student "enzymes" learn over the course of the simulation, which can change their rate. Asking students about unanswered questions on enzyme kinetics allows them to connect what they have learned from the classroom portion of our course or other experiences to the lab. This discussion also helps instructors identify whether any major misconceptions are still held by students. In our course, instructors lead this discussion in the lab section one week after the activity to allow students time to reflect on their answers. However, this larger discussion could also be done immediately after the small groups have an opportunity to come up with answers, ensuring that all students are able to engage with the questions even if they are unwilling to speak up in a large group.

List of Materials Needed to Complete this Lesson:
• 2x2 plastic building bricks (such as LEGO TM ) in three different colors. At least 60 bricks of each main color and 30 bricks of inhibitor color are needed per group of students. • Fast-acting adhesive to glue together inhibitor bricks. • Small opaque bags or boxes to hold and store bricks.
We used cloth drawstring bags (~6" by 10"), in which we also stored the materials between semesters. • Printouts/digital copies of activity handout (Supporting File S1. Breaking Bricks -Student Activity Handout) • Timers or stopwatches. • Access to a computer and graphing software OR graph paper.

TEACHING DISCUSSION
Our objective for this lesson was to create a more engaging, physical, and active introduction to key concepts in enzyme kinetics in the presence and absence of a competitive inhibitor. We believe that this lesson was effective at introducing students to key concepts in enzyme kinetics and inhibition by modeling a hydrolysis reaction.

Effectiveness of the Lesson
Comparisons between our pre-lesson and post-lesson survey responses suggest that, overall, students appear to better understand key concepts in enzyme kinetics after the lesson and corresponding instruction in the lecture portion of the course. In our post-lesson assessment, significantly more students were able to correctly answer questions about the effect of inhibitors and correctly interpret the Michaelis-Menten and Lineweaver-Burk plots (Figure 2). This increase in comprehension is likely due to a combination of material covered in the lecture portion of our course and accompanying problem set, as well as engaging in the Breaking Bricks activity in the lab. However, the proportion of students correctly answering questions about how to interpret the Lineweaver-Burk plot was somewhat lower than the corresponding Michaelis-Menten representation of the data even after the lesson (Figure 2). This is not surprising, since creating and analyzing Lineweaver-Burk plots was not included in the Breaking Bricks activity, though it was discussed in the lecture. We discuss how to create and manipulate these types of graphs when analyzing the beta-galactosidase experimental data students collect in the second laboratory session which follows after the activity. Graphing of enzyme kinetics data using the Lineweaver-Burk plot could be easily added to the data analysis portion of the "Breaking Bricks" activity if understanding and interpreting this type of graph is not addressed elsewhere in the course.
In our post-activity survey, we incorporated a set of published attitudinal questions used to assess a related physical model of enzyme kinetics (12) to evaluate whether our students found the activity worthwhile. The majority of students perceived that this lesson was greatly or moderately helpful for visualization of several different key concepts of enzyme kinetics, including the effect of increasing substrate concentration on the rate of reaction, the concept of V max , and the effect of adding a competitive inhibitor to the reaction ( Figure 3). We note that survey data showed that overall students found the lesson less helpful in visualizing K m . We expect that this is because the increase in K m observed in the presence of a competitive inhibitor is more easily visualized on a Lineweaver-Burk plot or with a broader array of substrate concentrations than used in this lesson.

Student Reactions to the Lesson
Overall, students and faculty instructors have enjoyed completing this lesson throughout the three years we have used it. Enzyme kinetics can be a difficult topic for instructors to teach and students to understand, so using a physical model with familiar objects such as plastic bricks to model hydrolysis of a disaccharide made understanding the underlying concepts easier for our students. In fact, in an open-ended comment on our post-lesson survey, one student remarked: "This activity helped me conceptualize and start connecting kinetics concepts. Prior to this activity enzyme kinetics felt very abstract and thus very confusing." In addition, many students found the physical act of disassembling the bricks enjoyable, especially since building with plastic blocks can be a common childhood pastime. We note that there was usually a large amount of laughter, shouting, and friendly competition for "enzymes" with the greatest V max from students (and instructors!) while engaged in the activity in our classes. One student said, "I think I didn't really understand how all the concepts linked until I created the graphs, which could have been done with any other data, but using the LEGOs was very interactive and fun!" As instructors, we also found ourselves in the final discussion talking with students about how humans acting as enzymes were not perfectly representative of how an enzyme works mechanistically, suggesting that students were engaged in higher order comparison and evaluation of this activity.

Suggestions for improvements or adaptations
While we have used this lesson as an introduction to enzyme kinetics in our course-based laboratory focused on betagalactosidase, this lesson is broadly adaptable as a physical model of enzyme kinetics and inhibition for any cell biology or beginning biochemistry course in either a classroom or laboratory setting. We believe that this lesson works best when incorporated as a simple, physical introduction to the topic of enzyme kinetics prior to more detailed experiments or problembased learning. While we have not taught this activity using the POGIL format as described by Moog et al,(20), our lesson could be easily reorganized such that students complete the "Exploration" phase of running the breaking brick simulation prior to "Term Introduction" of defining the enzyme, substrate, and product. Similar to the outcomes described in the POGIL format, students conducting this activity have the opportunity to practice hypothesis creation, data analysis, and scientific communication in addition to building content knowledge about enzyme kinetics.
Timing of when this activity is integrated into the curriculum is important for both student learning and student motivation. In a previous iteration of the course, we included this lesson after students had already conducted their beta-galactosidase experiment in the presence and absence of the competitive inhibitor IPTG and fit their experimental data to the Michaelis-Menten and Lineweaver-Burk plots. In that course structure, the majority of the students had already spent time thinking about enzyme kinetics and how inhibitors affect the enzyme and thus thought that the activity was too simplistic. Students in the revised version of the course appreciate the simplicity of the breaking brick activity as a beneficial and relatable introduction to enzyme kinetics before delving into a more complicated system like that of beta-galactosidase.
We have separated the act of doing the breaking brick activity and the wrap-up discussion into two sessions based on other experiments that are ongoing in our laboratory course. However, this lesson could be taught all in one 75-minute class period. In this case, we recommend that the instructor introduce the lesson, followed by the class dividing into small groups of students to complete the breaking brick activity, generate graphs, and think through their extensions, limitations and concerns. The class would end by reconvening as a group for a final discussion. In addition, if time permits, students could also test out their proposed ideas for non-competitive inhibition and graph them to see whether the data follows the model which predicts a change in V max and no change in K m .
While we typically use this activity in an in-person laboratory setting, we believe that the Breaking Bricks activity and its suggested extensions could also be helpful for a remote-taught course or replacement for an enzyme-kinetics laboratory activity. Materials like plastic building bricks may be available at home for some students or are easily ordered and shipped to them by their home institution. Students could perform the activity as described and record their data individually either synchronously or asynchronously. Student groups can then work together to pool data on shared spreadsheets, answer conceptual questions, and complete ORID-style structured discussions about their observations.

SUPPORTING MATERIALS
• S1. Breaking Bricks -Student Activity Handout. We provide physical and digital copies of this handout to each lab partner as instructions for the lesson. • S2. Breaking Bricks -Introductory Slides for Enzyme Kinetics Activity. These slides provide introduction and guiding questions for the activity. • S3. Breaking Bricks -Enzyme Kinetics Activity Datasheet. This sample spreadsheet provides one way to organize the data collected from the activity. • S4. Breaking Bricks -Discussion Questions. These questions are assigned after the laboratory session and serve as a starting point for the second session's wrap-up conversation. • S5. Breaking Bricks -Pre-Assessment. This anonymous survey was administered before the lesson and contains conceptual and graph interpretation questions about key concepts in enzyme kinetics and inhibition. • S6. Breaking Bricks -Post-Assessment. This anonymous survey was administered after the lesson. It contains the same conceptual and graph interpretation questions as the pre-assessment, and also includes several attitudinal questions and a place for students to include comments and feedback about the lesson. A Google Form version of both assessments and an answer key are available on request.

ACKNOWLEDGMENTS
We would like to thank the instructors and students of BISC 220 in Spring 2018, 2019, and 2020 for providing feedback on several iterations of this lesson, Tess Killpack for assistance with survey data analysis, Leah Okumura for contributing to the original design of this experiment, and Steven Biller for photography. Funding for supplies to develop the lesson was provided by a Wellesley College Educational Research and Development grant to J.A.R. 9 Breaking Bricks: A Hands-On Model of Enzyme Kinetics and Inhibition Table 1. Breaking Bricks lesson teaching timeline.

Activity Description Estimated Time Notes Preparation for Activity
Assembly of supplies 1. Make one copy of handout for each pair of students.
2. Assemble pairs of 2x2 plastic bricks as substrate and add 60 pairs to each container.
3. Use fast-acting adhesive glue to securely attach pairs of 2x2 plastic bricks as inhibitor.
About 30-45 minutes to assemble 10 sets of substrates and glue inhibitors, additional time required to allow glue to dry • Student activity handout is provided in Supporting File S1. Breaking Bricks -Student Activity Handout.
• The numbers of substrate (60) and inhibitor (15) brick pairs are provided per group. Calculate how many bricks are needed by determining how many groups of 2-3 will be formed in your course.