Question

how many light quanta are required for the reduction of one molecule of n a d p+
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Answer 1

Answer:

functioning to fix CO2. The formation of triose phosphates in the carboxylation and reduction phases of the Calvin–Benson cycle requires both energy (ATP) and reducing equivalents (NADPH) produced in the thylakoid membranes of chloroplasts in the light.

3 CO2 + 3 ribulose 1,5-bisphosphate + 3 H2O + 6 NADPH + 6 H+ + 6 ATP →

6 triose phosphates + 6 NADP+ + 6 ADP + 6 Pi

Under steady state photosynthesis, one sixth of the triose phosphates formed leaves the Calvin–Benson cycle for the net synthesis of starch and sucrose while the remaining five sixths are used to replenish ribulose 1,5-bisphosphate. The regeneration phase requires additional ATP for forming the primary CO2-acceptor.

5 triose phosphates + 3 ATP → 3 ribulose 1,5-bisphosphate + 3 ADP

Hence, one complete turn of the Calvin–Benson cycle utilizes 9 ATP and 6 NADPH for the fixation of three CO2 into one triose phosphate