The light reactions occur entirely in the thylakoid lumen wh

The light reactions occur entirely in the thylakoid lumen, whereas the dark reactions occur in the stroma. Why is it necessary that the two groups of reactions occur in different compartments?

Solution

Light reaction need spliting of water molecule which releases electrons. These electrons move through PS1 & PS2 complexes and finally produce Assimilation power. That is ATP & NADPH. Rhis assimilation power is the Driving force for Dark reaction. Inorder to generate ATP, there is need to form, proton gradients, which is possible only in Thylakoids. The enzymes responsible for Dark reaction like RUBISCO present in srroma, so dark reaction or Calvin cycle occur only in stroma