Guided Reading - Enzymes and Energy III
1. Catalysts increase reaction rates by lowering the activation energy of a reaction. 
True    False
2. An enzyme elevated in the plasma of men with prostate cancer is 
A. alkaline phosphatase.
B. catalase.
C. creatine kinase.
D. acid phosphatase.
3. Enzymes ______________ the rate of a specific chemical reaction. 
A. decrease
B. increase
C. have no effect on
4. Ribozymes are RNA molecules that act as 
A. hormones.
B. cofactors.
C. enzymes.
D. inhibitors.
5. If NAD becomes reduced it is a(n) 
A. reducing agent.
B. oxidizing agent.
C. zymogen.
D. allosteric inhibitor.
6. The pH optima for all digestive enzymes are approximately equal to the pH of blood. 
True    False
7. An atom or molecule that is oxidized is also a reducing agent. 
True    False
8. The phosphatase found in bone would have a pH optimum that is ______________ than the pH optimum of the phosphatase found in the prostate gland. 
A. higher
B. lower
C. the same as
9. In bioenergetic pathways, as intermediates are acted upon by enzymes, the ultimate result is the release of 
A. lactate.
B. ATP.
C. free energy.
D. enzymes.
10. Coenzymes are organic molecules that are required for proper function of some enzymes. 
True    False
11. The principle that reversible reactions will be driven from the side of the equation where the concentration is lower to the side where the concentration is higher is known as the law of mass action. 
True    False
 12. Consuming extra niacin and riboflavin in the diet will provide extra energy for body functions. 
True    False
 
13. A defect in the enzyme which converts phenylalanine into tyrosine is characteristic of the disease 
A. phenylketonuria.
B. albinism.
C. lactose intolerance.
D. maple-syrup disease.
 
14. A reducing agent donates electrons to a molecule. 
True    False
 
15. During reduction, a molecule or atom 
A. gains protons or gains electrons.
B. loses protons or gains electrons.
C. gains protons or loses electrons.
D. loses protons or loses electrons.
 
16. In some instances RNA can act as an enzyme. 
True    False
 
17. The vitalist concept was defeated because of fermentation experiments involving 
A. yeast.
B. bacteria.
C. amoebae.
D. paramecia.
 
18. FAD is derived from vitamin 
A. B-12.
B. B-3, niacin.
C. B-2, riboflavin.
D. B-6.
 
19. An inborn error in lipid metabolism may cause all of the following diseases EXCEPT 
A. Tay-Sachs disease.
B. homocystinuria.
C. hypercholesteremia.
D. Gaucher's disease.
 
20. A defect in the enzyme that catalyzes the formation of melanin from DOPA results in 
A. phenylketonuria.
B. albinism.
C. lactose intolerance.
D. maple-syrup disease.
 
21. Which of the following does NOT affect the activity of an enzyme? 
A. the organ the enzyme is in
B. concentration of enzyme and substrate molecules
C. concentration of cofactors and coenzymes
D. pH and temperature
22. Which of the following is NOT a characteristic of a catalyst? 
A. is not changed itself at the end of the reaction
B. does not change the nature of the reaction
C. can change the final result of the reaction
D. increases the rate of the reaction
23. Enzymes in a metabolic pathway act antagonistically to produce a final product. 
True    False
 24. In the reaction (H2O + CO2 ? H2CO3), increasing the concentration of H2O would 
A. decrease the concentration of H2CO3.
B. increase the concentration of H2CO3.
C. increase the concentration of CO2.
D. have no effect on either CO2 or H2CO3 concentrations.
 
25. Which of the following is NOT true of catalysts? 
A. They are unchanged by the reaction catalyzed.
B. They allow endergonic reactions to become exergonic reactions.
C. They increase the amount of energy released by a chemical reaction.
D. All of these choices are not true.