Question

question 44
which of the following does not occur during the calvin cycle?
carbon fixation
oxidation of nadph
release of oxygen
regeneration of the co2 acceptor

Explanation:

• Carbon fixation: It is a key step in the Calvin cycle where \(CO_2\) is incorporated into organic molecules (e.g., \(CO_2\) combines with RuBP (ribulose - 1,5 - bisphosphate)).
• Oxidation of NADPH: NADPH is used as a reducing agent in the Calvin cycle. During the reduction phase of the Calvin cycle (reduction of 3 - phosphoglycerate to glyceraldehyde - 3 - phosphate), NADPH is oxidized to \(NADP^+\).
• Release of oxygen: Oxygen release occurs during the light - dependent reactions of photosynthesis. In the light - dependent reactions, water is split (\(2H_2O

ightarrow O_2 + 4H^++4e^-\)) to provide electrons for the electron transport chain. The Calvin cycle is the light - independent (dark) reaction and does not release oxygen.

• Regeneration of the \(CO_2\) acceptor (RuBP): After the formation of glyceraldehyde - 3 - phosphate, some of it is used to regenerate RuBP through a series of enzymatic reactions so that the Calvin cycle can continue.

Answer:

release of oxygen