Chapter 6 review

1. The end products of the light dependent reactions of photosynthesis area. ADP, H2O, NADPHb. ADP, PGAL, RuBP (RuDP)c. ATP, CO2, H2Od. ATP, NADPH, O2

2. The function of water in photosynthesis is toa. combine with CO2

b. supply electrons in the light-dependent reactions c. Transport H ions in the light-independent (dark) reactions d. Provide O2 for the light-independent reactions

3. When hydrogen ions are pumped out of the chloroplast stroma, across the thylakoid membrane, and into the thylakoid space, the result is

a. the reduction of NAD+

b. the restoration of the Na-K balance across the membrane.c. the creation of a proton gradient.d. the lowering of pH in the chloroplast stroma.

4. You incubate isolated intact mitochondria in a buffered solution containing succinate (an oxidizable substrate) and ADP plus Pi. Upon adding cyanide (an inhibitor of Complex IV, cyto-chrome oxidase which is part of the electron transport chain), you examine the effect on oxygen consumption and the production of ATP. What do you predict?

A. Oxygen will not be consumed, and no ATP will be produced.B. Oxygen will be consumed, but no ATP will be produced.C. Oxygen will not be consumed, but ATP will be produced.D. Oxygen will be consumed, and ATP will be produced.

Use the following answers for questions 5-8A. FADHB. NAD+

C. Oxygen (O2)D. NADP+

5. An intermediate electron acceptor for oxidations that occur in both glycolysis and in Krebs cycle reactions

6. An intermediate electron acceptor for oxidations that occur in the light dependent reaction of photosynthesis

7. Coenzyme that transfers electrons from the Krebs cycle to the mitochondrial electron-transport chain at a lower energy level than that of the electrons entering at the beginning of the chain

8. The final electron acceptor for cellular respiration

9. Which of the following describes a metabolic consequence of the shortage of oxygen in muscle cells?

a. An increase in blood pH due to an accumulation of lactic acid.b. No ATP production due to the absence of substrate-level phosphorylation.c. A buildup of lactic acid in the muscle tissue due to lactic acid fermentation.d. A decrease in the oxidation of fatty acids due to a shortage of ATP.

10. Which of the following best supports the claim that organisms of different domains share a common ancestor?

a. Photosynthesis occurs in chloroplasts and the citric acid cycle occurs in mitochondria.b. Glycolysis occurs in both prokaryotic cells and eukaryotic cells.c. Anaerobic respiration is common in prokaryotic cells but not in eukaryotic cells.d. Some plants have evolved better ways to fix CO2 through C4 and CAM photosynthesis.

11. Which of the following is an example of active transport across a membrane?a. The movement of water from a nephron into the collecting duct of the kidney.b. The movement of water from the inside of a cell into a surrounding hypertonic

medium.c. The movement of Na+ into a neuron as a nerve impulse is generated.d. The movement of H+ into a thylakoid disc during photosynthesis.

12. Mitochondria are found in most eukaryotic cells and contain their own DNA and ribosomes that are similar to those typical of many prokaryotic cells. Which of the following statements is justified by these observations?

a. The mitochondrion is the only location where eukaryotic cells can synthesize ATP.b. An ancestral cell most likely engulfed an aerobic prokaryote in a relationship that

proved beneficial for both cells.c. Mitochondrial membranes provide abundant surface area for reactions because of the

infoldings called christae. d. The mitochondrion plays a role in respiration, but it also stored the cells extra mRNA.

13. A study of the metabolic rate in a terrestrial community shows that the energy captured in photosynthesis exceeds the energy released by respiration. Which of the following situations is occurring?

a. Community biomass is decreasing. b. Community biomass is increasing.c. A climax community has been reached.d. The first law of thermodynamics is not in effect.

14. Which of the following questions is most relevant to understanding the Calvin-Benson cycle?a. How does chlorophyll capture light?b. How is ATP used in the formation of 3-carbon carbohydrates?c. How is NADP+ reduced to NADPH?d. How is ATP produced in chemiosmosis?

15. The chemical reaction for photosynthesis is

6 CO2 + 12 H2O + light energy → C6H12O6 + 6 O2 + 6 H2O

If the input water is labeled with a radioactive isotope of oxygen, 18O, then the oxygen gas released as the reaction proceeds is also labeled with 18O. Which of the following is the most likely explanation?

a. During the light reactions of photosynthesis, water is split, the hydrogen atoms combine with the CO2, and oxygen gas is released.b. During the light reactions of photosynthesis, water is split, removing electrons and protons, and oxygen gas is released.c. During the Calvin cycle, water is split, regenerating NADPH from NADP+, and oxygen gas is released.d. During the Calvin cycle, water is split, the hydrogen atoms are added to intermediates of sugar synthesis, and oxygen gas is released.

16. The figures below illustrate the similarities between ATP synthesis in mitochondria and chloroplasts.

The figures can best assist in answering which of the following questions?a. Do electron transport chains create a gradient so that ATP synthase can generate ATP molecules?b. What are the sources of energy that drive mitochondrial and chloroplast electron transport systems?c. What is the optimal temperature at which ATP synthase chemically converts ADP and a phosphate group into one molecule of ATP?d. What is the evolutionary relationship between the ATP synthase in mitochondria and the ATP synthase in chloroplasts?

Questions 17-19

20. What most likely causes the trends in oxygen concentration shown in the graph above?a. The water becomes colder at night and thus holds more oxygen.b. Respiration in most organisms increases at night.c. More organisms are respiring at night than during the day.d. Photosynthesis produces more oxygen than is consumed by respiration during the day.

21. In the Arctic Ocean, the predominant primary producers are phytoplankton. Phytoplankton are consumed by zooplankton, which in turn are eaten by codfish. In years when there is more open water (less ice coverage), there are more zooplankton and fish than in years with less open water (more ice coverage). Based on the graph above, the difference is most likely because

a. when there is less open water, light is blocked from the zooplankton, so they cannot produce as much food for the fishb. when there is more open water, the temperature is warmer, so the zooplankton and fish populations increase in sizec. the ice blocks the light, so in years with more ice coverage, there is less photosynthesis by the phytoplanktond. the ice increases the light available for photosynthesis, so primary production increases and zooplankton populations increase in size

22. Students in a class measured the mass of various living organisms. They then kept the organisms in the dark for 24 hours before remeasuring them. None of the organisms were provided with nutrients during the 24-hour period. The data are as follows.

Organism Starting Mass (g) Final Mass (g)Elodea (submerged aquatic plant) 15.10 14.01Goldfish 10.10 9.84Sea anemone 25.60 24.98

Which of the following is the best explanation for the pattern of change in mass of the organisms over time? a. Water loss due to evaporation

b. Cellular respirationc. The law of conservation of matterd. Growth and reproduction

23. Which of the following best describes the function of the coenzymes NAD+ and FAD in eukaryotic cellular respiration?

a. They participate in hydrolysis reactions by accepting protons from water molecules.b. They participate directly in the phosphorylation of ADP to ATP.c. They serve as final electron acceptors in the electron transport chain.d. They accept electrons during oxidation-reduction reactions.

24. Two nutrient solutions are maintained at the same pH. Actively respiring mitochondria are isolated and placed into each of the two solutions. Oxygen gas is bubbled into one solution. The other solution is depleted of available oxygen. Which of the following best explains why ATP production is greater in the tube with oxygen than in the tube without oxygen?

a. The rate of proton pumping across the inner mitochondrial membrane is lower in the sample without oxygen. b. Electron transport is reduced in the absence of a plasma membrane. c. In the absence of oxygen, oxidative phosphorylation produces more ATP than does fermentation. d. In the presence of oxygen, glycolysis produces more ATP than in the absence of oxygen.

25. To test the hypothesis that a particular plant synthesizes storage lipids by using glyceraldehyde 3-phosphate (G3P) from photosynthesis, a researcher plans to use radiolabeled precursors to track the molecules through the biosynthetic pathway. Which of the following radiolabeled precursors is most appropriate for the researcher to use?

a. 15

N-labeled N2, because atmospheric nitrogen is fixed to amino acids by photosynthesis

b. 14

C-labeled CO2, because atmospheric carbon is fixed to carbohydrates by photosynthesis

c. 35

S-labeled methionine, because amino acids are incorporated into lipids during photosynthesis

d. 32

P-labeled phosphate, because lipids are stored in plants as phospholipidsPractice math grid-ins:

1.

How much carbon (in g/m2) is released into the atmosphere as a result of the metabolic activity of herbivores? Give your answer to the nearest whole number.

2.

Based on the data shown, calculate the average rate of increase in oxygen consumption for animals acclimated to 5oC as the temperature increases from 10°C to 30°C. Give the answer in mL O2/g/h/°C to the nearest tenth.

3. The enzyme phosphofructokinase (PFK) is an allosterically regulated enzyme that catalyzes the following reaction.

Fructose-6-phosphate + ATP Fructose-1,6-bisphosphate + ADP

The graph below shows that at certain concentrations ATP inhibits the enzyme, whereas AMP activates it. According to the information presented in the graph, when the concentration of fructose-6-phosphate is 0.5 mM, how many times more active is PFK in cells with 1 mM ATP + 0.1 mM AMP than in cells with 5 mM ATP? Express your answer to the nearest whole number.

Practice short FRQs:

1.

2.

3. In a certain prairie community, a dominant prairie grass species has recently been infected with a virus that disrupts one of the electron transport proteins in the chloroplasts of infected cells.

(a) Describe the most likely effects on cellular processes (be specific as to which processes and moleculesare most likely to be directly affected).(b) Describe and explain the most likely effects on individual infected plants.

4. Matter continuously cycles through an ecosystem. A simplified carbon cycle is depicted below.

(a) Identify the key metabolic process for step I and the key metabolic process for step II, and briefly explain how each process promotes movement of carbon through the cycle. For each process, your explanation should focus on the role of energy in the movement of carbon.

(b) Identify an organism that carries out both processes.