Question

Which of the following correctly compares linear electron flow to cyclic electron flow in the electron transport chain of photosynthesis.

Group of answer choices

Cyclic electron flow produces more glyceraldehyde-3-phosphate (GAP) and less 3-phosphoglycerate (3-PGA) than linear electron flow.

Cyclic electron flow produces more 3-phosphoglycerate (3-PGA) and less glyceraldehyde-3-phosphate (GAP) than linear electron flow.

Cyclic electron flow produces more ATP and less NADPH than linear electron flow.

Cyclic electron flow produces more NADPH and less ATP than linear electron flow.

None of the above.

Answer 1

Answer: Cyclic electron flow produces more ATP and less NADPH than linear electron flow.

When electron flow takes place after it goes from PSII to PSI it produces a molecule of ATP, if its a lines electron flow from PSI it goes through fd and forms NADPH using NADP+ reductase enzyme. If it is cyclic, the electron instead of going from fd to form NADPH it comes back again to PQ and through cytochrome complex, it produces another molecule of ATP. So after one-electron flow, the linear produces one molecule of ATP and NADPH while from cyclic electron flow two molecules of ATP is produced and no NADPH.