What are the major similarities between oxidative phosphorylation and non-cyclic photophosphorylation?

In terms of similarities, both processes involve generating a proton electrochemical gradient across a membrane, by pumping protons from an area of lower concentration to a higher concentration. This creates a proton motive force, that causes protons to diffuse through the ATP synthase enzyme embedded in the membrane, which synthesises ATP from ADP and Pi. In both cases, proton pumps are powered by the release of energy as high energy electrons pass down a chain of electron carriers (the electron transport chain).

Oxidative phosphorylation occurs on the inner mitochondrial membrane and the high energy electrons originate from reduced coenzymes NADH and FADH2 (from the Krebs Cycle, Link Reaction and Glycolysis), whereas non-cyclic photophosphorylation occurs on the thylakoid membrane in the chloroplasts, and the electrons originate from water which are excited by photons of light. The inner mitochondrial membrane contains 3 proton pumps but the thylakoid membrane contains 1. The terminal electron acceptor in oxidative phosphorylation is O2, which combines with protons to form water, but in non-cyclic phosphorylation, it is NADP+. Water is produced in oxidative phosphorylation, but water is required in non-cyclic phosphorylation (along with the input of light energy).