Metabolism Practice Test & Answers

Which of the following describes some aspect of metabolism? correct answer: synthesis of macromolecules, breakdown of macromolecules, and control of enzyme activity Which term precisely describes the cellular process of breaking down large molecules into smaller ones? correct answer: catabolism Which of the following statements correctly describes catabolic pathways? correct answer: they release energy as they degrade polymers to monomers Which of the following is (are) true for anabolic pathways? correct answer: they consume energy to build up polymers from monomers Which of the following is true for all exergonic reactions? correct answer: the reaction proceeds with a net release of free energy A chemical reaction that has a positive 'G is correctly described as correct answer: endergonic The hydrolysis of ATP to ADP and inorganic phosphate (ATP + H2O-ADP- +Pi): correct answer: -has a ´G of about -7 kcal/mol under standard conditions. -involves hydrolysis of a terminal phosphate bond of ATP. -can occur spontaneously under appropriate conditions. When 10,000 molecules of ATP are hydrolyzed to ADP and Pi in a test tube, about twice as much heat is liberated as when a cell hydrolyzes the same amount of ATP. Which of the following is the best explanations for this observation? correct answer: cells convert some of the energy of ATP hydrolysis into other forms of energy besides heat ATP generally energizes a cellular process by correct answer: coupling free energy released by ATP hydrolysis to free energy needed by other reactions Which of the following reactions is most likely to be coupled to the reaction ATP + H2O-ADP +Pi ( 'G = -7.3 kcal/mol)? correct answer: +Pi-EP ('G = +5 kcal/mol)