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?

Question

Daniel Arnold · Accepted Answer

ATP and NADPH

Light energy is utilized to split water into protons and molecules of oxygen O2 during the light-dependent reaction that takes place in the thylakoid membranes of chloroplasts. 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 generates NADPH and ATP. During the process, protons are also transferred from the stroma, raising the stroma's pH, and Mg2+ is transferred from the thylakoid to the stroma. In this light-independent reaction, Mg2+-catalyzed CO2 fixation uses up the ATP and NADPH produced in the light-dependent reaction.

Oliver Antoine · Answer

undefined The light-dependent reactions of photosynthesis occur in the thylakoid membrane of the chloroplast, while the light-independent reactions occur in the stroma of the chloroplast. The chemical relationship between the light-dependent and light-independent (carbon fixation) reactions of photosynthesis is that the products of the light-dependent reactions (ATP and NADPH) are used as energy sources in the light-independent reactions.