Question

In stage 2 of photosynthesis, NADP+ becomes NADPH by adding an H+. Where does the H+ come from?

Answer 1

The right answer is d. splitting of water.

- The photons of light, at the level of the thylakoid membrane, excite the chlorophylls a (excited state) which lose electrons supported by a set of molecules (photosynthetic chain) up to a final acceptor, NADP +

- The return to a ground state of chlorophyll a (non-excited state) implies the dissociation of water (= photolysis of water or photo-oxidation of water), which leads to the release of electrons (recovered by the oxidized chlorophyll that returns to its ground state), H + protons and the production of oxygen (released into the environment of the plant).

- NADP + accepts electrons (released by chlorophyll) and protons and is reduced to the compound NADPH, H +.

Answer 2

The correct answer is D Splitting water.

Hope this helps! :)