Chapter 8 Guided Reading
1. During the light reactions of photosynthesis, the synthesis of _______ is coupled to the
diffusion of protons.
2. Atmospheric CO2 enters plant leaves through openings called _______.
3. In the 1800s, the summarized chemical reaction for photosynthesis was incorrect
because it left out _______ as a product.
4. In noncyclic photophosphorylation, the electrons for the reduction of chlorophyll in
photosystem II come from _______.
5. When _______ are exposed to light and CO2, four-carbon compounds are the first
carbon-containing products.
6. During the process of _______, rubisco catalyzes the reaction of RuBP with oxygen.
7. A group of scientists led by _______ conducted experiments demonstrating that RuBP
is the CO2 acceptor in the dark reactions of photosynthesis.
8. When researchers shifted isolated chloroplasts from a low pH solution to a more
alkaline solution, ATP synthesis occurred, even in the absence of light. This experiment
was used to support the _______ mechanism of ATP formation in chloroplasts.
9. During cyclic photophosphorylation, the energy of photons is converted to the
chemical energy of the product, _______.
10. In C3 plants, the Calvin–Benson cycle occurs in the chloroplasts of _______ cells,
whereas in C4 plants the cycle occurs in the _______ cells.
11. In both photosynthesis and respiration, _______ synthesis is coupled to the diffusion
of protons across a membrane.
12. The dark reactions take place in the (dark/light) _______.
13. NADP is the abbreviation for _______.
14. The Calvin–Benson cycle is sometimes called the _______.
15. The O2 found in Earth’s atmosphere is generated from the photosystem _______ of
noncyclic photophosphorylation.
16. During cyclic photophosphorylation, _______ rather than NADP+ receives the
electron from ferredoxin.
17. The most abundant enzyme in the biosphere is _______.
18. The absorption spectrum of chlorophyll a is (different from/similar to) _______ the
action spectrum of chlorophyll a.
19. The wide range of wavelengths that photons can have is shown by the _______.
STUDY GUIDE QUESTIONS
1. The main purpose of photosynthesis is to
a. consume CO2.
b. produce ATP.
c. convert light energy to chemical energy.
d. produce starch.
2. Which of the following best represent the components that are necessary for
photosynthesis to take place?
a. Mitochondria, accessory pigments, visible light, water, and CO2
b. Chloroplasts, accessory pigments, visible light, water, and CO2
c. Mitochondria, chlorophyll, visible light, water, and O2
d. Chloroplasts, chlorophyll, visible light, water, and CO2
3. Chlorophyll is suited for the capture of light energy because
a. certain wavelengths of light raise it to an excited state.
b. in its excited state chlorophyll gives off electrons.
c. chlorophyll’s structure allows it to attach to thylakoid membranes.
d. All of the above
4. Plants give off O2 because
a. O2 results from the incorporation of CO2 into sugars.
b. plants do not respire because they photosynthesize.
c. water is the initial proton donor, leaving O2 as a photosynthetic by-product.
d. All of the above
5. Cyclic and noncyclic electron flow are used in plants to
a. meet the ATP demands of the Calvin–Benson cycle.
b. avoid producing excess NADPH + H+.
c. balance ATP and NADPH + H+ ratios in the chloroplast.
d. All of the above
6. Which of the following statements concerning the light reactions of photosynthesis is
true?
a. Photosystem I can operate independently of photosystem II.
b. Photosystems I and II are activated by different wavelengths of light.
c. Photosystems I and II transfer electrons and create proton gradients across the
thylakoid membrane.
d. All of the above
7. ATP is produced during the light reactions via
a. CO2 fixation.
b. chemiosmosis.
c. reduction of water.
d. All of the above
8. Because of the properties of chlorophyll, plants need adequate __________ light to
grow properly.
a. green
b. blue and red
c. infrared
d. ultraviolet
9. Which of the following statements concerning the Calvin–Benson cycle is not true?
a. Light energy is not required for the cycle to proceed.
b. CO2 is assimilated into sugars.
c. RuBP is regenerated.
d. It uses energy stored in ATP and NADPH + H+.
10. Which of the following statements concerning rubisco is true?
a. Rubisco is an enzyme.
b. Rubisco catalyzes both the beginning steps of photorespiration and the Calvin–Benson
cycle.
c. Rubisco is the most abundant protein on earth.
d. All of the above
11. Which of the following begins the Calvin–Benson cycle and is the commitment step
that results in the entire pathway being carried out?
a. 3PG is reduced to G3P using ATP and NADPH + H+.
b. RuBP is regenerated.
c. CO2 and RuBP join forming 3PG.
d. As a cycle, it can start at any point.
12. The Calvin–Benson Cycle results in the production of
a. glucose.
b. starch.
c. rubisco.
d. G3P.
13. Which of the following statements regarding photorespiration is true?
a. Photorespiration is a metabolically expensive pathway.
b. Photorespiration is avoided when CO2 is abundant.
c. Photorespiration reduces the overall CO2 that is converted to carbohydrates.
d. All of the above
di.
14. The fixation of CO2 by PEP carboxylase functions to
a. concentrate CO2 for use in photosynthetic cells.
b. allow plants to close stomata without having photorespiration occur.
c. allow plants to photosynthesize in the dark.
d. Both a and b
15. CAM plants differ from C4 plants in that
a. CO2 is stored as malic acid.
b. photosynthesis can occur at night in these plants.
c. their stomata close during periods that favor photorespiration.
d. they use PEP carboxylase to fix CO2.
16. Which of the following statements is true regarding the relationship between
photosynthesis and cellular respiration in plants?
a. Photosynthesis occurs in specialized photosynthetic cells.
b. Cellular respiration occurs in specialized respiratory cells.
c. Cellular respiration and photosynthesis can occur in the same cell.
d. Both a and c