During photosynthesis, the energy given up by electrons as they move through the electron transport chain is used to
generate an electrochemical H+ gradient across a membrane.
Which portion of the photosynthetic apparatus is involved in the oxidation or splitting of water?
manganese cluster
Which of the following represents a reactant or input for the light reaction of photosynthesis?
H2O
What is the main role of the pigment molecules within the antenna or light-harvesting complex?
Absorb photons and transfer light energy to the reaction center chlorophyll
Which of the following statements regarding photosystem II is FALSE?
Photosystem II strips an electron from water for direct transfer to the electron transport chain.
Which of the following contributes to the electrochemical gradient that exists across the thylakoid membrane during photosynthesis?
The electron transport chain.
The splitting of water to produce H+ and oxygen in the thylakoid lumen.
The depletion of H+ in the stroma during NADPH production.
The pumping of H+ into the thylakoid lumen by electron transport proteins.
Which of the following best represents the path of electron flow that occurs during photosynthesis?
H2O-->P680-->Final Electron AcceptorElectron transport chain-->P700
What are the primary functions of both photosystems I and II?
produce ATP and NADPH
Which portion of the photosynthetic apparatus absorbs light?
both photosystem I and photosystem II
How might a plant cope with the fact that the Calvin cycle uses more ATP than NADPH, yet produces roughly the same amount of both energy intermediates in photosystems I and II?
Photosynthesis can revert from a noncyclic to cyclic electron flow.
Which order of events for the Calvin cycle is correct?
III. Carbon fixation
I. Reduction
II. Regeneration of the CO2 acceptor (RuBP)
Where does the Calvin cycle occur?
chloroplast stroma
This molecule combines with CO2 to form the 3-carbon substance, 3-phosphoglycerate.
ribulose biphoshpate (RuBP)
Which of the following requires both ATP and NADPH?
the Calvin cycle only
Using 14CO2 as a radioactive tracer, which of the following molecules would be the last to incorporate 14C within the Calvin cycle?
ribulose biphosphate (RuBP)
Which of the following is NOT a product of the Calvin cycle?
NADPH
All of the following are required for the Calvin cycle EXCEPT
H2O.
Which of the following statements about photorespiration is INCORRECT?
It utilizes the enzyme PEP carboxylase rather than Rubisco to produce 3-phosphoglycerate.
Which of the following has the highest photosynthetic efficiency in hot and dry environments?
C4 plants
Which is TRUE of succulent plants such as cacti or pineapple?
They produce 4-carbon malate in the first step of carbon fixation
CAM (crassulacean acid metabolism) plants such as cacti differ from standard C4 plants such as corn in which of the following way?
CAM plants are limited to producing CO2 for the Calvin cycle during the day, while C4 plants produce CO2 for the Calvin cycle both during the day and at night.
Which of the following is the primary advantage of C4 plants over C3 plants?
C4 plants minimize photorespiration compared with C3 plants.
C4 plants can produce sugars more efficiently than C3 plants under hot, arid conditions.
C4 plants can produce CO2 needed for sugar production in the Calvin cycle more efficiently than C3 plants.
Relative to C3 plants, C4 plants can keep their stomata closed more frequently to limit water evaporation, yet can still produce significant CO2 needed for sugar production