name of the enzyme lactase was created by adding the suffix to part of the name of the substrate –ase lactose. ★ Circle the active site in the enzyme in the figure above An enzyme speeds up a chemical reaction which converts a substrate or substrates to a product or products. The products are released from the enzyme and the enzyme returns to its original state, so the enzyme is ready to act on another substrate molecule. Thus, an enzyme molecule can be reused over and over. For example, a single molecule of the enzyme lactase can speed up the digestion of many many molecules of lactose. ★ The following equation shows the digestion of lactose. Lactase Lactose --------- > Glucose + Galactose Use E to indicate the enzyme, S to indicate the substrate, and P to indicate the products. Circle the molecule that is a protein, and use arrows to indicate the molecules that are sugars. Experiment 1 - Can the sugar lactose be digested without any enzyme? To find out whether the enzyme lactase is needed to digest the sugar lactose, you will test whether lactose breaks down to glucose and galactose in two different conditions: (1) with no enzyme and (2) when the enzyme lactase is present. ★ First, predict what you think will happen. For each column, circle the equation that describes what you think will happen. Prediction with No Enzyme Prediction with the Enzyme Lactase No Enzyme Lactase Lactose -------- > Glucose + Galactose Lactose -------- > Glucose + Galactose Or Or No Enzyme Lactase Lactose -------- > Lactose Lactose -------- > Lactose (no glucose produced) (no glucose produced) To test whether your predictions are correct, you will use glucose test strips to test whether glucose has been produced. Procedure 1. One member of your group should prepare Tube 1 with 10 mL of lactose solution. 2. Another member of your group should prepare Tube 2 with 10 mL of lactose solution and 1 mL of lactase solution. Put on a glove, put your thumb on the top of the tube and turn the tube upside down several times to mix the two solutions. 3. Wait 3 minutes to allow time for lactose to break down to glucose and galactose.
name of the enzyme lactase was created by adding the suffix –ase to part of the name of the substrate lactose. ★ Circle the active site in the enzyme in the figure above An enzyme speeds up a chemical reaction which converts a substrate or substrates to a product or products. The products are released from the enzyme and the enzyme returns to its original state, so the enzyme is ready to act on another substrate molecule. Thus, an enzyme molecule can be reused over and over. For example, a single molecule of the enzyme lactase can speed up the digestion of many many molecules of lactose. ★ The following equation shows the digestion of lactose. Lactase Lactose --------- > Glucose + Galactose Use E to indicate the enzyme, S to indicate the substrate, and P to indicate the products. Circle the molecule that is a protein, and use arrows to indicate the molecules that are sugars. Experiment 1 - Can the sugar lactose be digested without any enzyme? To find out whether the enzyme lactase is needed to digest the sugar lactose, you will test whether lactose breaks down to glucose and galactose in two different conditions: (1) with no enzyme and (2) when the enzyme lactase is present. ★ First, predict what you think will happen. For each column, circle the equation that describes what you think will happen. Prediction with No Enzyme Prediction with the Enzyme Lactase No Enzyme Lactose -------- > Glucose + Galactose Or No Enzyme Lactose -------- > Lactose (no glucose produced) Lactase Lactose -------- > Glucose + Galactose Or Lactase Lactose -------- > Lactose (no glucose produced) To test whether your predictions are correct, you will use glucose test strips to test whether glucose has been produced. Procedure 1. One member of your group should prepare Tube 1 with 10 mL of lactose solution. 2. Another member of your group should prepare Tube 2 with 10 mL of lactose solution and 1 mL of lactase solution. Put on a glove, put your thumb on the top of the tube and turn the tube upside down several times to mix the two solutions. 3. Wait 3 minutes to allow time for lactose to break down to glucose and galactose.
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