Question

multiple choice question
the nadph produced in photosynthesis is made when ______.

○ photosystem ii passes electrons to nadp⁺ along with h⁺ to form nadph
○ photosystem ii passes photons to nadp⁺ along with h⁺ to form nadph
○ photosystem i passes electrons to nadp⁺ along with h⁺ to form nadph
○ photosystem i passes electrons to nadp⁺ along with water to form nadph

Explanation:

To determine how NADPH is produced in photosynthesis, we analyze each option:

• Option 1: Photosystem II does not pass electrons to \( \text{NADP}^+ \) to form NADPH; that's the role of Photosystem I. So this is incorrect.
• Option 2: Photosystems pass electrons, not photons, to \( \text{NADP}^+ \). Photons are absorbed to excite electrons, not passed directly. So this is incorrect.
• Option 3: In photosynthesis, Photosystem I (PSI) receives electrons (after they pass through the electron transport chain from Photosystem II), and then PSI passes these electrons to \( \text{NADP}^+ \) along with \( \text{H}^+ \) (protons) to form \( \text{NADPH} \) (the reaction is \( \text{NADP}^+ + 2e^- + \text{H}^+

ightarrow \text{NADPH} \)). This matches the correct process.

• Option 4: Water is split in Photosystem II to release electrons, protons, and oxygen. NADPH formation involves \( \text{H}^+ \) (protons), not water directly being passed to \( \text{NADP}^+ \) with electrons from PSI. So this is incorrect.

Answer:

C. photosystem I passes electrons to \( \text{NADP}^+ \) along with \( \text{H}^+ \) to form NADPH (assuming the third option is labeled C; if the original options had different labels, adjust the label but keep the description)