Question

which statement about thioredoxin is consistent with these data? thioredoxin is a regulatory molecule, shutting down calvin cycle reactions by acting as an alternative to nadp+ as the final electron acceptor during the light reactions. thioredoxin is an electron carrier protein that participates in the electron transport chain during photophosphorylation. thioredoxin is an integral protein component of the thylakoid membrane that ensures that the membrane remains impermeable to protons. thioredoxin is an enzyme that functions in carbon fixation as an alternative to the calvin cycle enzyme rubisco. thioredoxin is a regulatory molecule, becoming activated via light - induced changes and then activating prk by shifting it from an inactive to an active conformation. wild type thiorexloxin mutant double mutant: thioredoxin and prk condition activity of phosphoribulokinase (prk) light dark light dark light dark 100% 99% 5% 6% 100% 6%

Explanation:

Thioredoxin is a regulatory molecule. In the wild - type, PRK activity is 100% in light and 6% in dark. In the thioredoxin mutant, PRK activity is low in both light and dark. In the double mutant (thioredoxin and PRK), PRK activity is high in light and low in dark similar to wild - type. This indicates that thioredoxin is a regulatory molecule that is activated via light - induced changes and then activates PRK by shifting it from an inactive to an active conformation.

Answer:

The statement "Thioredoxin is a regulatory molecule, becoming activated via light - induced changes and then activating PRK by shifting it from an inactive to an active conformation" is consistent with the data.