Please Explain Oxidative Phosphorylation?

Question

Hi I'm a college student studying microbiology. Right now I'm studying the way animal cells make ATP through the Mitochondrion. there are three things that have to take place for ATP to be created Glycolysis, the Citric Acid Cycle, and Oxidative Phosphorylation. I have some understanding of glycolysis in that it takes glucose and makes pyruvate. A little less understanding of the Citric Acid cycle, all I understand is that it makes some NADH and ADP. And zero understanding of how Oxidative Phosphorylation works. Can you please explain oxidative Phosphorylation to me?

Answer 1

Oxidative phosphorylation, the Electron Transport Chain, and chemiosmosis are all terms frequently utilized to refer to the final step of cellular respiration, and are all related even though they mean slightly different things.

Oxidative phosphorylation refers to the production of ATP through the reduction of oxygen. Remember that glycolysis and the Citric Acid Cycle produce very little ATP, 2 molecules each. However, both of those steps resulted in the reduction (gaining electrons) of electron carriers. The electron carriers from glycolysis and the Citric Acid Cycle (NADH and FADH2) take their electrons to the electron transport chain (ETC).

The ETC is a series of electronegative proteins in the inner mitochondrial membrane (meaning they can accept electrons). The electron carriers donate their electrons (along with accompanying protons) to the chain. The electrons are passed down the chain and used to generate energy. Once the electrons are in a low energy state, they are accepted by Oxygen (the final electron acceptor) to form water. The energy from the movement of the electrons is used to pump protons (H+) outside the membrane.

Eventually, there will be enough H+ outside the membrane to create a concentration gradient, which will drive the protons to move back through the membrane into the matrix. The protons will move across the membrane using the enzyme ATP synthase. The movement of the protons flowing down their gradient provides the energy for ATP synthase to phosphorylate (add a phosphate) to ADP, forming ATP. This process produces much more ATP than the first two steps (~32).

In shorter terms: oxidative phosphorylation involves the movement of electrons to generate energy. The electrons are eventually accepted by Oxygen to form the waste product water. The energy from the movement of all those electrons is used to set up a concentration gradient that lets ATP synthase (an enzyme) create a large amount of ATP.