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    Photolysis of H2O in photosynthesis, how the hell does it happen? It's not in our course, it just says "H2O molecules are split into 2H+ and 1/2 O2 in the presence of photons.

    I'm just curious, tried to do some research but there doesnt seem to be much on it, does anyone actually know how this happens?
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    light energy is used to split the water molecule, hydrogen into protons and electrons and the oxygen is a waste product used in resp etc.

    thats all we need to know :awesome:
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    I know that, but I'm not a "Thats all you need to know" person :P The solution is posted in the chem section if anyone is curious
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    i guess it's could be like Cl2 breaking to give Cl dot free radicals in homolytic fission.

    and like the electrons on alkali metals that get excited in colured flame tests, the electrons on these hydrogens get promoted and leave the hydrogen ion.
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    Photolysis is the splitting of water via light i.e. photons.

    H20 ----(light)---> 2e- + 2H+s + 1/2O2 (an oxygen atom)

    As far as I know, you don't need to know why light splits water, but you do need to know why it's important.
    Photolysis occurs in the thylakoid space. The 2 electrons it produces are used to replace the pair lost from Photosystem II/P680 at the beginning of Non Cyclic Photophosphorylation and therefore stabilise it.

    The H+s (as far as I know) leave the thylakoid space, enter the stroma and are coupled with the pair of electrons released by the second electron accepter at the end of the Z scheme (Non cyclic PP) in order to reduce NADP+ into NADPH/H+.

    Obviously NADPH/H+ is one of the products that go on to enter the Calvin Cycle, so yeah, photolysis is pretty important.

    Hope that helps.
 
 
 

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