A grasshopper leaps into the air from the edge of a vertical cliff, as shown in ?Fig. P3.57.? Find (a) the initial speed of the grasshopper and (b) the height of the cliff.
Review for Chapter 15 1. What do the following indicators tell you about whether a reaction can proceed as written a) The standard free-energy change is positive b) The free-energy change is positive c) The reaction is exergonic 2. Can the thermodynamic property ΔG°' be used to predict the speed of a reaction in a living organism Why or why not 3. Which of the following statements concerning the free energy change (ΔG) is false a. The energy change for a reaction depends only on the initial and final states, and is independent of the path taken. b. The overall energy change for a reaction could be calculated by summing the energy changes for a series of separate reactions that could convert the reactants to the products. c. The rate of a reaction can be determined from the energy change. d. The energy change is a function of the concentrations of the products and reactants at start. 4. The ΔG°' for the reaction Citrate isocitrate is +6.64 kJmol = +1.59 kcalmol . The ΔG°' for -1 -1 the reaction Isocitrate α-Ketoglutarate is -267kJmol = -63.9 kcalmol What is the ΔG°' for the conversion of citrate to α-Ketoglutarate Is that reaction exergonic or endergonic, and why 5. The standard state of a solution is taken as a. 1 atmosphere of pressure. b. the pure solute. c. 1 molar concentration. d. none of the above. 6. Consider this rxn which has a ΔG° = +0.4 kJ/mol. A + B C + D 1 M A, 1 M B, 0.1 M C and 0.1 M D are added to a container at room temperature. Which of the following statements is true a. The reaction will proceed in the forward direction to reach equilibrium. b. The reaction will proceed in the backward direction to reach equilibrium. c. The reaction will not proceed in either direction; it is already at equilibrium. d. Cannot be determined from the information provided. 7. Biochemists use a modified value for standard ΔG values because a. all reagents are not at a 1 molar concentration. b. the pH in living systems is seldom, if ever, near 0. c. the concentration of water is not at 1 molar concentration. d. the reagents are not one molar and the pH = 7. e. All of these justify why biochemists use a special ΔG value. 8. The standard state usually used in biochemistry (ΔG°') includes a. all concentrations at 1 M. b. all concentrations at 1 M, except for [H ], which is 10 M. c. same as a), but at 25° C. d. same as b), but at 25° C. 9. Which of the following statements apply to anabolism a. proceeds in stages b. requires energy c. requires reducing agents d. all of these 10. "Oxidation" refers to a. the loss of oxygen. b. the gain of oxygen. c. the loss of electrons. d. the gain of electrons. 11. Consider the reaction of alcohol dehydrogenase. A. Which is the oxidizing agent a. Ethanol b. NAD + c. Acetaldehyde d. NADH e. H+ B. Which molecule loses electrons a .Ethanol b. NAD c. Acetaldehyde d. NADH e. H + 12. The oxidation of nutrients supplies the energy to produce ATP. a. True b. False 13. In biological redox reactions, hydrogen ions are usually transferred along with electrons. a. True b. False 14. The energy released during metabolism of nutrients can be used to synthesize ATP from ADP and phosphate. a. True b. False 15. ATP is a good source of energy to run metabolic reactions for all the following reasons, except: a. The pyrophosphate bond has a high energy of hydrolysis. b. The sugar group is very reactive. c. The bonds between the phosphates are acid anhydrides. d. The phosphate groups can combine readily with other molecules. 16. What happens to the entropy when ATP is hydrolysed to ADP a. Entropy increases b. Entropy decreases. c. Entropy doesn't change. d. ATP has no entropy.