photosynthesis

The pH of the inner thylakoid space has been measured, as have the pH of the stroma and of the cytosol of a particular plant cell. Which, if any, relationship would you expect to find? 

• a. The pH of the stroma is higher than that of the thylakoid space but lower than that of the cytosol.
• b. The pH of the stroma is lower than that of the other two measurements.
• c. There is no consistent relationship.
• d. The pH within the thylakoid is less than that of the stroma.

The light reactions of photosynthesis supply the Calvin cycle with

• a. light energy.
• b. ATP and NADPH.
• c. sugar and O₂.
• d. H₂O and NADPH.

Figure 8.1 shows the absorption spectrum for chlorophyll a and the action spectrum for photosynthesis. Why are they different?

• a. Bright sunlight destroys photosynthetic pigments.
• b. Aerobic bacteria take up oxygen, which changes the measurement of the rate of photosynthesis.
• c. Green and yellow wavelengths inhibit the absorption of red and blue wavelengths.
• d. Other pigments absorb light in addition to chlorophyll a.

What does the pumping of hydrogen ions into the intermembrane space  provide in chloroplasts during the light reactions?

• a. formation of glucose, using carbon dioxide, NADPH, and ATP
• b. reduction of water to produce ATP energy
• c. establishment of a proton gradient across the thylakoid membrane
• d. movement of water by osmosis into the thylakoid space from the stroma

The reactions that produce molecular oxygen (O₂) take place in

• a. the light reactions alone.
• b. the chloroplast, but are not part of photosynthesis.
• c. both the light reactions and the Calvin cycle.
• d. neither the light reactions nor the Calvin cycle.

Which of the following are products of the light reactions of photosynthesis that are utilized in the Calvin cycle?

• a. CO₂ and glucose
• b. ADP, _i, and NADP⁺
• c. ATP and NADPH
• d. electrons and H+

What compound provides the reducing power for the Calvin cycle reactions? (*think electron carrier)

• a. NADPH
• b. ATP
• c. NADH
• d. NAD⁺

Where are the molecules of the electron transport chain found in plant cells?

• a. outer membrane of mitochondria
• b. thylakoid membranes of chloroplasts
• c. stroma of chloroplasts
• d. cytoplasm

A spaceship is designed to support animal life for a multiyear voyage to the outer planets of the solar system. Plants will be grown to provide oxygen and to recycle carbon dioxide. Because the spaceship will be too far from the sun for photosynthesis, an artificial light source will be needed.

• a. UV light
• b. yellow light
• c. a mixture of blue and red light
• d. green light

Which of the following does not occur during the Calvin cycle?

• a. release of oxygen
• b. carbon fixation
• c. oxidation of NADPH
• d. consumption of ATP