Answer:
The Chemical Coupling:
A coupling reaction in organic chemistry is a general term for a variety of reactions where two fragments are joined together with the aid of a metal catalyst.
The Conformational Coupling:
The basic idea, as originally proposed by Robin Irvine, is that stimulation of the IP3 receptor (IP3R) by store emptying induces a conformation change that is transferred to the channel in the plasma membrane through a direct protein-protein interaction (3)
The Chemiosmotic Coupling
For approximately twenty years, it has been generally agreed, in accordance with the chemiosmotic theory, that the coupling of electron transfer reactions to ATP synthesis is mediated by a proton electrochemical gradient, often alternatively called a protonmotive force, generated across these membranes by electron