What is the chemical relationship between the light dependent and the light independent (carbon fixation) reactions of photosynthesis? In what part of the chloroplast does each occur?

1 Answer
Mar 18, 2017



During light dependent reaction which is occurring in thylakoid membranes of chloroplast light energy is used to split water in to proton and molecular oxygen O2

8 Photons of light + 2H 2 O + 2NADP + + 10#H^+#stroma ---> O2 + 2NADH + 12#H^+#lumen

3ADP3- +3Pi2- + 3#H^+# + 12H +lumen ---> 3ATP 4- + 3H2O + 12#H^ +#stroma

also produces ATP and NADPH.

Protons are also transfered during the process from stroma which increases the pH of stroma and Mg2+ is transfered from thylakoid to stroma

Ih light independent reaction, the ATP and NADPH which are formed during light dependent reaction are used up in fixing CO2 in Calvin cycle catalysed by Mg2+.