AP Biology: Cellular Respiration Review Fall 2017

1. ATP hydrolysis (removing a P group) is 7. In the conversion of glucose and O2 to CO2 and H2O, which a. endergonic molecule becomes reduced? b. exergonic c. chemoautotrophic Which molecule is oxidized? glucose d. anabolic e. endothermic 8. NAD+ is called an __electron carrier____. 2. Which of the following cellular metabolic processes is active in all cells, regardless of the presence or absence of oxygen? Its reduced form is __NADH______. a. the citric acid cycle b. electron transport 9. How much more ATP can be generated by respiration than by c. glycolysis fermentation? Explain why? d. fermentation Cellular respiration = 38 e. pyruvate oxidation (link reaction) Fermentation = net gain of 2 Fermentation allows glycolysis to occur (net gain of 2) 3. Which statement regarding glycolysis is false? a. A 6-C carbon sugar is broken to two 3-C molecules. 10. Which of the following reactions is incorrectly paired with its b. Two ATP molecules are consumed. location? c. Glycolysis requires oxygen. a. ATP synthesis – inner membrane of the mitochondria, d. A net sum of two ATP molecules is generated. mitochondrial matrix and cytosol e. Glycolysis occurs in the cytosol. b. fermentation – cytosol c. glycolysis – cytosol 4. During which process is most ATP generated in the cell? d. substrate-level phosphorylation – cytosol and mitochondrial a. glycolysis matrix b. the citric acid cycle e. citric acid cycle – cristae of the mitochondria (citric acid cycle c. electron transport coupled with chemiosmosis takes place in the matrix of the mitochondria) d. fermentation e. pyruvate oxidation 11. When pyruvate is converted to acetyl CoA, (link reaction between glycolysis and citric acid cycle)

5. Which of the following is a function of the electron transport a. CO2 and ATP are produced chain? b. a multienzyme complex removes a carboxyl group, transfers a. cycling NADH back to NAD+ electrons to NAD+ and attaches a coenzyme b. using the intermediates from the citric acid cycle c. one turn of the citric acid cycle is completed c. breaking down pyruvate (glycolysis) d. NAD+ is regenerated so that glycolysis can continue to d. increasing the number of protons in the mitochondrial matrix produce ATP by substrate level phosphorylation (electrons are moved to the intermembrane space) e. phosphofructokinase is activated and glycolysis continues e. consuming excess ATP

12. How many molecules of CO2 are generated for each molecule 6. Which statement best describes the role of the inner of acetyl CoA introduced into the citric acid cycle? mitochondrial membrane? a. 1 a. It acts as an anchor for the membrane-associated enzymes of b. 2 Acetyl CoA contains 2 carbons cellular respiration. c. 3 b. It allows for the establishment of a proton gradient. d. 4 c. It separates the mitochondria’s environment from that of the e. 6 cytosol. d. It anchors enzymes and allows for the establishment of the 13. Which of the following statements correctly describes the proton gradient, but it is also involved in separating the role of oxygen in cellular respiration? contents of the mitochondria from the cytosol. a. It is reduced in glycolysis as glucose is oxidized. e. It anchors enzymes, allows for the establishment of the b. It combines with H+ diffusing through ATP synthase to proton gradient, and is involved in separating the contents of produce H2O. an electron is also needed to produce water the mitochondria from the cytosol. This answer is listed on the c. It provides the activation energy needed for oxidation to answer key but I don’t agree with the last part – separating occur. contents… I think that better describes the out membrane. d. It is the final electron acceptor for the electron transport chain. e. It combines with the carbon removed during the citric acid d. a and b are correct. cycle to form CO2. e. a, b and c are correct.

14. In the chemiosmotic mechanism, 19. Muscle cells in oxygen deprivation gain which of the a. ATP production is linked to the proton gradient established following from the reduction of pyruvate? by the electron transport chain. a. ATP b. the difference in pH between the intermembrane space and b. ATP and NAD+ The NAD+ will return to glycolysis the cytosol drives the formation of ATP. allowing for the production of a small amount of ATP + + c. the flow of H through ATP synthases rotates a rotor and rod, c. CO2 and NAD driving the hydrolysis of ADP. d. ATP, alcohol and NAD+ d. the energy released by the reduction and subsequent e. ATP and CO2 oxidation of electron carriers transfers a phosphate group to ADP. 20. Glycolysis is considered one of the first metabolic pathways e. the production of water in the mitochondrial matrix by the to have evolved because reduction of oxygen leads to a net flow of water out of the a. it relies on fermentation, which is characteristic of archaea mitochondria. and bacteria b. it is found only in prokaryotes, whereas eukaryotes use

15. When glucose is oxidized to CO2 and water, approximately mitochondria to produce ATP 66% of its energy is transformed to c. it produces much less ATP than does the electron transport a. heat chain and chemiosmosis b. ATP d. it produces ATP only by substrate level phosphorylation and c. a proton-motive force does not involve redox reactions d. molecular movement e. it is nearly universal, is located in the cytosol and does not

e. NADH involve O2

16. Which of the following is incorrect concerning oxidative 21. Which of the following substances produces the most ATP phosphorylation? per gram? a. It produces 2.5 ATP for every NADH this is oxidized. a. glucose, because it is the starting place for glycolysis b. It involves the redox reactions of the electron transport chain. b. glycogen or starch, because they are polymers of glucose The reduction of oxygen (to produce water) happens in the c. fats, because they are highly reduced compounds matrix of the mitochondria. d. proteins, because of the energy stored in their tertiary c. It involves an ATP synthase located in the inner structure mitochondrial membrane. e. amino acids, because they can be fed directly into the citric d. It uses oxygen as the final electron donor. acid cycle e. It is an example of chemiosmosis.

17. Which of the following statements correctly describes a metabolic effect of cyanide, a poison that blocks the passage of electrons along the electron transport chain? a. The pH of the intermembrane space becomes much lower than normal. b. Electrons are passed to oxygen, causing cells to explode. c. Alcohol would build up in the cell. d. NADH supplies would be exhausted, and ATP synthesis would cease. e. No proton gradient would be produced, and ATP synthesis would cease. Initially there would be no electrons moving along the electron transport chain.

18. Fermentation produces less ATP than cellular respiration because a. NAD+ is regenerated by alcohol or lactate production, without the electrons of NADH passing through the electron transport chain. b. pyruvate still contains most of the electrons that were present in glucose. c. its starting reactant is pyruvate and not glucose.