A chloroplast is observed switching from non-cyclic to cyclic photophosphorylation. What internal cellular condition typically triggers this regulatory shift in electron flow?
Q1. A chloroplast is observed switching from non-cyclic to cyclic photophosphorylation. What internal cellular condition typically triggers this regulatory shift in electron flow?
Answer: Low ATP concentration
Explanation: Cyclic flow occurs when ATP levels are low relative to NADPH. High NADPH triggers this to balance the Calvin cycle requirements.