Question

What is the effect of boiling chloroplasts on the subsequent reduction of DPIP?

A) Boiling enhances DPIP reduction.
B) Boiling has no effect on DPIP reduction.
C) Boiling inhibits DPIP reduction.
D) Boiling changes the color of DPIP without affecting reduction.

Answer 1

Boiling chloroplasts denatures proteins and enzymes, inhibiting the production of NADPH and thus the subsequent reduction of DPIP, which relies on the reduced power generated by light-dependent reactions.

Step-by-step explanation:

What is the effect of boiling chloroplasts on the subsequent reduction of DPIP? The correct answer is C) Boiling inhibits DPIP reduction. Boiling chloroplasts will denature the proteins and enzymes that are essential for the light-dependent reactions that generate the reduced power necessary for driving the reduction of DPIP. In the Thylakoid membrane of the chloroplasts, Photosystems I and II capture light energy and use it to pump protons across the membrane, creating a proton gradient that is then used to produce ATP and reduce NADP+ to NADPH via the electron transport chain. When NADPH is not produced due to boiling and denaturation, it cannot contribute to the reduction of DPIP, therefore boiling has an inhibitory effect on this process.