BIOLOGY 12: CHAPTER 6 - REVIEW WORKSHEET ENZYMES PART A: CHAPTER REVIEW 1. List the 2 cellular organelles that transform one form of energy into another form. 2. Name the 2 processes that permit a flow of energy from the sun through all living things? 3. Define energy. Do chemicals, energy, or both cycle through living things? 4. Define the First Law of Thermodynamics. Can energy be converted from one form to another form? 5. Why must a cell always take in energy in order to continue living? 6. What is meant by the Second Law of Thermodynamics? What form of energy is lost to the surroundings? 7. Name the molecule that is the immediate source of energy in cells. What is it composed of? Where are the high-energy bonds found? 8. Define metabolism. What are the advantages of having metabolic pathways in a cell? 9. What are enzymes? Why are they important? Are they specific? How are they named? 10. Why are enzymes absolutely necessary to the continued existence of a cell? PART B: OBJECTIVE CHAPTER TEST 1. When cells require energy for synthetic reactions, they spend. 1
2. In the diagram below, list the two cellular processes that allow for energy transformations on lines a and b. One lines c and d, list the organelles responsible for each cellular process. a. b. carbohydrate + O2 c. d. CO2 + H2O ATP + heat 3. According to the Second Law of Thermodynamics, one usable form of energy (can/cannot) be completely converted into another usable form. 4. is the non-usable form of energy that is easily lost to the surroundings. 5. Every ATP molecule is composed of the base (a), the sugar (b), and three (c) groups. The wavy lines in the formula for ATP indicate (d) - phosphate bonds. 6. The equation ADP + ATP is energy (requiring/releasing) 7. E1 E2 E3 A > B > C > D In this metabolic pathway, the letter B stands for the (a) as the result of the action of Enzyme 1. However, as a result of the action of Enzyme 2, B represents a (b). Each and every reaction in a cell requires a specific (c). 8. The generalized equation for enzymatic action is. This equation shows that the enzyme and the substrate form a temporary complex. 9. is an enzyme that removes hydrogen atoms from a substrate. Substrate Enzyme a. Lipid a. b. Urea b. c. Starch c. d. Ribonucleic acid d. 10. Less heat is needed to bring about a chemical reaction within a cell because enzymes will (increase/decrease) the energy of activation of a reaction. 11. The site is the place where the substrate fits onto the enzyme for orientation so that the reaction takes place. 12. Use the following terms to label this diagram: substrate, enzyme, active site, product, enzyme substrate complex. 2
13. When the substrate binds to the enzyme, the enzyme undergoes a slight change in shape to achieve maximum fit. This concept is termed the model. 14. Suppose two amino acids join together to form a dipeptide. This type of reaction is considered a (synthetic / degradation) reaction. 15. Catalase is an enzyme that breaks down hydrogen peroxide into water and oxygen. Plot the results of the data below in the accompanying graph. Millilitres of Oxygen Temperature Formed per Minute ( C) 100 10 200 20 300 30 600 40 300 50 100 60 16. On the basis of the above graph, at which temperature did the catalase exhibit the greatest activity? 17. Why did the activity of catalase decrease as the temperature continued to increase above 40 C? 18. Explain why hydrogen peroxide can be broken down by the enzyme catalase but another substrate, such as maltose, cannot be broken down by catalase.. 3
Substrate Concentration Amount of Product Formed (Milligrams/millilitre) (Milligrams/millilitre) 0 0 10 100 20 200 30 400 40 400 50 400 19. Study the table given above. Which substrate concentration will initially yield the maximum amount of product formed? (a) Explain why the amount of product formed does not increase as the substrate concentration goes beyond 30 milligrams/ml. (b) 20. Based on the 2 tables presented below, which shows irreversible inhibition? Table A Substrate Concentration Inhibitor Concentration Amount of Product Formed (milligrams/millilitre) (milligrams/millilitre) (milligrams/millilitre) 20 0 200 20 10 100 20 20 50 20 40 0 100 40 400 Table B Substrate Concentration Inhibitor Concentration Amount of Product Formed (milligrams/millilitre) (milligrams/millilitre) (milligrams/millilitre) 20 0 200 20 10 0 20 20 0 20 40 0 100 40 0 21. In inhibition, an inhibitor binds to an enzyme at a site other than the active site. 22. Two environmental factors that can change the shape of an enzyme are (a) and (b). 23. Enzymes may have a non-protein helper called a(n) (a) or an organic molecules called a(n) (b). 24. is the loss of electrons or the removal of hydrogen atoms. For questions 27-31, use the following answers to match with the words below. a. inhibitor b. ATP c. enzyme d. extreme temperature 25. denatured 26. substance that can compete with a substrate 27. energy currency of the cell 28. substance that can speed up one particular reaction True (T) or False (F) If the statement to be false, rewrite the statement as a true one. 29. Enzymes, being molecules that speed up chemical reactions, are required in photosynthesis and cellular metabolism. 30. The shape of an inhibitor molecule is very similar to the shape of the enzyme s substrate. 4
31. High temperatures and extreme ph can cause an enzyme to denature. 32. All enzymes function at the same ph. 33. The First Law of Thermodynamics states that one usable form of energy cannot be completely converted into another usable form. 34. What are T3 and T4? Where are they secreted from? What are their effects on the body? 35. What is calcitonin? Under what conditions is it secreted? 5