When one hydrogen is added to NAD in photosynthesis how many electrons are accepted?

When one hydrogen atom is added to NAD+ (Nicotinamide adenine dinucleotide) during photosynthesis, it typically involves the transfer of two electrons. This process occurs during the light-dependent reactions, where NADP+ is reduced to NADPH. The addition of hydrogen not only adds the electron but also a proton, contributing to the formation of NADPH, which is crucial for the Calvin cycle in the subsequent stages of photosynthesis.