Evolution cells evolved 2.1 billion years ago as a result of nutrient shortage pressures. These cells are more efficient at using available sources because of the compartmentalization of their life processes. These organelles (the compartments) restrict chemical reactions to certain areas and with that more complex reactions can go on in each organelle, where the required enzymes are concentrated. The more complex organization also requires more chromosomes chromosomal structure – changed to linear chromosomes and there are multiple of them in each eukaryotic cell. The Role of the Nucleus It is a control center of the cell, which is processing inputs from the cytoplasm, stores genetic information and carries out instructions to regulate cell functions. The instructions are coded in DNA. The instructions include genes for making proteins, making RNA and to perform reproduction. Parts of the nucleus: Nuclear envelope made up of TWO phospholipid bilayer with nuclear pores. These – pores are large enough to transport RNA or proteins in and out of the nucleus. Nucleolus synthesizes rRNA to assemble the large and small subunits of the – ribosomes. These subunits only combine later in the cytoplasm. DNA always remains in the confined and protected area of the nucleus – Ribosomes are used to synthesize proteins. If the ribosomes are free floating in the cytoplasm, they synthesize proteins for the cell. If they are suspended on the rough ER, they form proteins that exit the cell. The Endomembrane System A set of organelles, which are functionally interrelated and located in the cytoplasm. Includes the nuclear envelope, rough and smooth endoplasmic reticulum, Golgi apparatus, cell membrane and other organelles that form from these listed ones (vesicles, vacuoles). All other organelles are listed in your book and you can take notes on them on your review sheets. Harvard cell animation –
Evolution cells evolved 2.1 billion years ago as a result of nutrient shortage pressures. These cells are more efficient at using available sources because of the compartmentalization of their life processes. These organelles (the compartments) restrict chemical reactions to certain areas and with that more complex reactions can go on in each organelle, where the required enzymes are concentrated. The more complex organization also requires more chromosomes – chromosomal structure changed to linear chromosomes and there are multiple of them in each eukaryotic cell. The Role of the Nucleus It is a control center of the cell, which is processing inputs from the cytoplasm, stores genetic information and carries out instructions to regulate cell functions. The instructions are coded in DNA. The instructions include genes for making proteins, making RNA and to perform reproduction. Parts of the nucleus: Nuclear envelope – made up of TWO phospholipid bilayer with nuclear pores. These pores are large enough to transport RNA or proteins in and out of the nucleus. Nucleolus – synthesizes rRNA to assemble the large and small subunits of the ribosomes. These subunits only combine later in the cytoplasm. DNA – always remains in the confined and protected area of the nucleus Ribosomes are used to synthesize proteins. If the ribosomes are free floating in the cytoplasm, they synthesize proteins for the cell. If they are suspended on the rough ER, they form proteins that exit the cell. The Endomembrane System A set of organelles, which are functionally interrelated and located in the cytoplasm. Includes the nuclear envelope, rough and smooth endoplasmic reticulum, Golgi apparatus, cell membrane and other organelles that form from these listed ones (vesicles, vacuoles). All other organelles are listed in your book and you can take notes on them on your review sheets. – Harvard cell animation
Unit%204%20notes%20--%20Principles%20of%20Life-5.docx