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Unformatted text preview: Enzymatic Action in Digestion Procedural Inquiries Preparation 1. What is hydrolysis? 2. Which major molecules must be hydrolyzed in digestion? 3. How do we simulate body conditions in setting up digestive experiments? Experimentation 4. How do we test for starch? 5. What is the principle behind the starch test? 6. How do we test for reducing sugars? 7. What is the principle behind the reducing-sugar test? 8. How do we test for proteins? 9. What is the principle behind the protein test? 10. How do we test for lipids? 11. What is the principle behind the lipid test? Additional Inquiries 12. What is digestion? 13. What is the role of enzymes in the digestive process? 14. What are bile salts? Key Terms Materials Needed Amylase Benedict’s Test Bile Biuret’s Test Carbohydrate Hydrolysis Lipid Lugol’s Iodine Micelles Pancreatin Protein Reducing Sugar Starch Water bath - 37°C Water bath - 100°C Test Tubes Test Tube Rack Test Tube Clamp Pipets Spot Plate Solutions 1% Starch 2% Maltose 2% Glucose Water (pH8) Iodine Benedict’s Solution Albumin 5% Pancreatin (pH8) Biuret’s Solution Cream (or Half and Half) Bile Salts Litmus Solution The foods we eat are composed primarily of carbohydrates, proteins, and lipids. In foods, however, these building blocks are often not in their most usable form and therefore must be digested before they can be transformed into whatever substance the body may need. Digestion is the process of breaking foods down into that usable form. The digestive process is a series of enzyme-catalyzed reactions. Recall that an enzyme is an organic catalyst, a molecule at least part protein whose function is to change the rate of a chemical reaction. Enzymes do not do anything that does not happen naturally. For instance, if you had had a steak for dinner last night, you really would not have needed those digestive enzymes for the digestive processes to have taken place. The only problem is that you would have starved to death waiting for digestion! Without digestive enzymes, what normally occurs in a few hours (digesting the steak) would take about 50 years to happen. Time is the justifying factor for enzyme catalysis. Enzymes, by today’s definition, increase the rate of biochemical reactions without being changed themselves. In this laboratory exercise we will demonstrate the principles of enzymatic action. • Preparation I. Introduction A. Hydrolysis Hydrolysis, the basic digestive breakdown mechanism, involves the splitting of a biological molecule by the addition of part of a water molecule. Study Figure 59-1 so that you understand exactly what is happening to the molecules being hydrolyzed. If necessary, go back to your lecture text or to your chemistry book to review the molecular intricacies of hydrolysis....
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This note was uploaded on 01/07/2012 for the course BIO 2402 taught by Professor Amirashaham-albalancy during the Spring '12 term at Collins.
- Spring '12