How the cyclic phosphorylation takes place in PS 1 independently according to chemiosomotic hypothesis ?
Dear student,
Cyclic phosphorylation occurs independently because the electrons excited from PSI is transferred back to PSI after passing through different sets of complex molecules. Excited electrons from PSI reaches ferrodoxin which is an electron carrier, further it reaches PQ (plastoquinone which is an electron and proton carrier) then electrons reaches cytochrome complex and plastocyanin finally the electrons return to PSI. When electron reaches PQ then it reduces to PQH2 by taking proton from stroma and transferring it to thylakoid lumen where the concentration of proton increases. Therefore the proton moves along the concentration gradient from thylakoid lumen to stroma with the help of CFo-CF1 complex generating energy in the form of ATP. So, this is in accordance with chemiosmotic hypothesis.
Regards
Cyclic phosphorylation occurs independently because the electrons excited from PSI is transferred back to PSI after passing through different sets of complex molecules. Excited electrons from PSI reaches ferrodoxin which is an electron carrier, further it reaches PQ (plastoquinone which is an electron and proton carrier) then electrons reaches cytochrome complex and plastocyanin finally the electrons return to PSI. When electron reaches PQ then it reduces to PQH2 by taking proton from stroma and transferring it to thylakoid lumen where the concentration of proton increases. Therefore the proton moves along the concentration gradient from thylakoid lumen to stroma with the help of CFo-CF1 complex generating energy in the form of ATP. So, this is in accordance with chemiosmotic hypothesis.
Regards