Why does the inside of the thylakoid membrane become positively charged during the light-dependent reactions?

The water-splitting complex is associated with the lumen side of the PSII. Splitting of water during the light-dependent reactions of photosynthesis releases protons, electrons, and oxygen. For two molecules of water split, four protons and one molecule of molecular oxygen are released in the lumen of the thylakoid. These released protons make the inside of the lumen more positive during the light-dependent phase of photosynthesis.

genewho genewho · Answer 2 · 2021-12-07T16:25:21+01:00

The thylakoid membrane is positively charged by protons released by dissociation of water during the light-dependent reactions and positive charges translocated from outside through the membrane during electron transport.

Light is absorbed by chlorophyll a molecules bound to proteins from the reaction center in the thylakoid membrane.

The dissociation of water molecules occurs due to the effect of light, and is defined as the interaction of one or more photons with a target molecule.

As the electrons pass through the acceptor chain, the protons are pumped into the thylakoid where they accumulate.

Protons are equivalent to H + ions, therefore the interior pH of the thylakoid drops, thereby establishing a pH difference across the membrane.

The electrons are transferred through the chain of electron transporting molecules that releases energy, this energy contributes to the pumping of hydrogen ions, from the stroma to the thylakoid and generating a proton gradient.

Therefore, we can conclude that the thylakoid membrane is positively charged since the transport of electrons is coupled to the movement of protons through the membrane, from the stroma towards the lumen of the thylakoid.

Learn more about thylakoid membrane here: brainly.com/question/477158