Refer to the table below summarizing data from an experiment conducted using chloroplasts isolated from spinach leaves.The chloroplasts were incubated with either no compound (control) or with compound A or B for 1 hour.Chloroplasts were then tested for the three functions listed at the top of the table. What do these data suggest about the role of NADPH in photosynthesis and why?
A) NADPH is required for photosynthesis because Calvin cycle function is blocked when noncyclic electron transport is inhibited.
B) NADPH is required for photosynthesis because Calvin cycle function is not blocked when cyclic electron transport is inhibited.
C) NADPH is required for photosynthesis because cyclic electron transport can function independently of noncyclic electron transport.
D) NADPH is not required for photosynthesis because cyclic electron transport can function even when noncyclic electron transport is inhibited.
E) NADPH is not required for photosynthesis because different chemical agents can inhibit cyclic and noncyclic electron transport separately.

Question

Refer to the table below summarizing data from an experiment conducted using chloroplasts isolated from spinach leaves.The chloroplasts were incubated with either no compound (control) or with compound A or B for 1 hour.Chloroplasts were then tested for the three functions listed at the top of the table.  What do these data suggest about the role of NADPH in photosynthesis and why?
A) NADPH is required for photosynthesis because Calvin cycle function is blocked when noncyclic electron transport is inhibited. 
B) NADPH is required for photosynthesis because Calvin cycle function is not blocked when cyclic electron transport is inhibited. 
C) NADPH is required for photosynthesis because cyclic electron transport can function independently of noncyclic electron transport. 
D) NADPH is not required for photosynthesis because cyclic electron transport can function even when noncyclic electron transport is inhibited. 
E) NADPH is not required for photosynthesis because different chemical agents can inhibit cyclic and noncyclic electron transport separately.

Quizplus · Accepted Answer

The data suggest that NADPH is required for photosynthesis because when noncyclic electron transport is inhibited (by compound A), the Calvin cycle function is blocked, while when cyclic electron transport is inhibited (by compound B), the Calvin cycle still functions normally. This indicates that NADPH, which is produced during noncyclic electron transport, is necessary for the Calvin cycle to proceed.

Refer to the Table Below Summarizing Data from an Experiment