Reading Guided - Enzymes and Energy I
1. Regulation of a metabolic pathway by the final product of the pathway is termed A. allosteric inhibition. B. end-product inhibition. C. negative feedback. D. Both end-product inhibition and negative feedback are correct.
2. The amount of entropy increases as bonds are broken to generate glucose from glycogen. True False
3. Abnormally high concentration of the BB form of creatine phosphokinase is associated with a myocardial infarction. True False
4. Addition of substrate when enzyme reaction rate is maximal results in A. additional product formation. B. less product formation. C. no change in product formation. D. enzyme destruction.
5. ______________ occurs when the product of a metabolic pathway binds to an enzyme and decreases enzymatic activity. A. Allosteric inhibition B. End-product therapy C. Second messaging D. Coupling
6. A common reducing agent used to couple chemical reactions in cells is A. riboflavin. B. niacin. C. NADH. D. FAD.
7. The substrate binds to the ______________ of the enzyme. A. allosteric site B. acidic site C. neutral site D. active site
8. Active enzymes are often called zymogens. True False
9. Most enzymes are lipids. True False
10. In an enzymatic reaction, when temperature is increased past the point of "optimal temperature," the enzyme starts to A. increase its catalytic activity. B. reduce its catalytic activity. C. increase its allosteric properties. D. increase product formation. 11. The reaction of adenosine diphosphate and phosphate generates adenosine triphosphate and energy. True False 12. is NAD derived from the vitamin A. B-12, cobalamin. B. B-3, niacin. C. B-2, riboflavin. D. B-6, pyridoxine. 13. The MM isoenzyme of creatine phosphokinase is found in diseased skeletal muscle. True False 14. The flow of energy in living systems is termed A. entropy. B. enthalpy. C. bioenergetics. D. bioluminescence. 15. The pH optimum for enzymes secreted by the stomach is higher than the pH optimum for enzymes secreted by the pancreas. True False 16. Addition of phosphate groups to a particular molecule is catalyzed by A. transaminases. B. phosphatases. C. isomerases. D. kinases. 17. Reactant molecules of enzyme action are called A. substrates. B. allosteric inhibitors. C. cofactors. D. products. 18. Hydrolysis reactions are catalyzed by A. dehydrogenases. B. hydrolases. C. isomerases. D. synthases.
19. Chemically reduced FAD has __________ extra hydrogen atom(s) bound to it. A. one B. two C. three D. no 20. Cellular respiration results in a(n) ______________ in entropy as glucose is broken down to form carbon dioxide. A. increase B. decrease C. no change
21. ______________ is the universal energy carrier. A. Glucose B. ATP C. ADP D. GTP
22. What technique has been affective in the treatment of inborn errors of metabolism such as SCID? A. allosteric inhibition B. gene therapy C. coenzyme activation D. None of the choices is correct.
23. At saturation, enzyme activity is maximal. True False
24. A common oxidizing agent used to couple chemical reactions in cells is A. riboflavin. B. niacin. C. NADH. D. FAD.
25. Exergonic reactions proceed with the release of energy. True False