[Folypeelarks]

Hi,  

I would like to ask you a question about NADP+ reduction through the photosynthesis to which even my teacher can't answer.I can't find any information.

Ok, through the process photolysis occurs and the water splits into 2 protons and 2 electrons (and oxygen too).2 electrons and 1 proton (hydride anion) are finally used for the reduction of NADP+ to NADPH.So what happens with the other proton?

 Some protons are constantly transferred across the membrane but as I know all of them are coming from the water splitting and at some point they finally would reach NADP+.So that means that with every photolysis per molecule their number would increase by 1.And I'm not sure that this is going to be ''healthy'' for the chloroplast.Can anyone explain me what happens with this excess of protons...is there another acceptor or this is not harmful..\or something else\?

[rjb]

Foolypeelarks,

The extra proton produced ends up in the lumen (I hope this is the right terminology!) of the chloroplast increasing the proton concentration and hence producing a proton gradient. The protons are forced through the F1FO ATP synthase complex which is used to produce ATP.

Kind Regards

R

[Folypeelarks]

Thanks,

Yes, this is the terminology.I actually know that the protons in the lumen are used for gradient production.I was just wondering that too many of them may harm the balance because the chloroplast increases the number of the protons through its whole life.

However, I think I find out the answer \When the chloroplast divides the protons are distributed equally in the daughter chloroplasts (actually in the lumen of their thylakoid membrane) where their number decreases nearly 2 times\