How does NADH transfer its energy?

Answer 1

Well - this is a loaded question.

Think of the electron transport chain as a hydroelectric dam. Essentially different molecules love electrons more than others, by transferring the electron from somebody that is ok with having an electron to some who loves electrons, will result in a more stable system; but by stabilizing the system you release energy (remember that unstable processes need the input of energy), this released energy in terms of the electron transport chain is used to pump protons (H+ atoms) across a membrane, this is like taking water from the bottom of a hydroelectric dam and then putting it at the top again. This process of electrons being transferred from NADH (who is ok with having electrons) all the way through a number of proteins to oxygen (O2, who ADORES electrons) will release a lot of energy; at each step the energy is used to pump a H+ across the membrane (or pump water to the top of the damn); once the H+ are at the top of the dam, they can run through the turbine-like protein called ATP synthase and this downhill motion will allow it to synthesize ATP; a relatively unstable molecule (because of the 3 anionic Pi's!), due to its instability it will pop off Pi's and power processes!

So it's mostly all about using relative molecule's preference for electrons, using the happiness (energy released) for giving an electron to someone who loves it more to power the pumping of H+ across a membrane (like pumping water to the top of a dam) and then, with the current of H+ ATP synthase can make ATP to power bodily/cellular functions :)

YouTube the electron transport chain, there are a lot of tutorials on it.