Chemiosmotic theory of ATP synthesis in the chloroplasts and mitochondria is based on (a) membrane potential (b) accumulation of Na ions (c) accumulation of K ions (d) proton gradient.
Option d Chemiosmotic coupling hypothesis is the most widely accepted explanation for oxidative phosphorylation in mitochondria and photophos phorylation in thylakoid membranes. Mitchell proposed the idea of chemiosmotic coupling. He suggested that a concentration gradient of protons is established across the mitochondrial membrane because there is an accumulation of hydrogen ions on one side of the mitochondrial membrane. The proton accumulation is necessary for energy transfer to the endergonic ADP phosphorylation process.
