Question

During the Hill Reaction and addition of DCPIP, would electron transport, proton pumping , the dark reactions, and ATP production stop?

Answer 1

The Hill Reaction depends on electrons released during the light dependent stage of photosynthesis being picked up by the blue electron acceptor DCPIP. The reaction can only occur if the
thylakoid membranes are illuminated as the light dependent stage stops in the dark.
DCPIP refers to "2,6-dichlorophenol-indophenol".
DCPIP is a dark blue solution that becomes lighter as it is reduced. DCPIP has a higher affinity for electrons than ferredoxin and the photosynthetic electron transport chain can reduce DCPIP as a substitute for NADP+, that is normally the final electron carrier in photosynthesis.

In the cell, NADP is the electron acceptor which is reduced in the light-dependent reactions, and which provides electrons and hydrogen for the light-independent reactions.

A photosynthetic organism captures light energy to drive the otherwise endergonic synthesis of molecules needed for the growth and maintenance of the organism. A central feature of photosynthesis is the conversion of light energy into redox energy, meaning that photon capture causes a component to change its redox potential from being relatively electropositive to being highly electronegative. The electrons released from this component are utilized to generate a proton-motive force, flowing either through a cyclic pathway back to re-reduce the original component or in a noncyclic pathway to reduce additional electron acceptors.