Editing Crista (section)

==Electron transport chain of the cristae==
[[File:Blausen_0644_Mitochondria.png|thumb|A [[mitochondrion]], with labeled cristae.]]
{{Main|Electron transport chain}}

[[NADH]] is oxidized into [[NAD+|NAD<sup>+</sup>]], H<sup>+</sup> [[ions]], and [[electrons]] by an [[enzyme]]. [[Flavin adenine dinucleotide|FADH<sub>2</sub>]] is also oxidized into H<sup>+</sup> ions, electrons, and [[Flavin adenine dinucleotide|FAD]]. As those [[electron]]s travel farther through the [[electron transport chain]] in the inner membrane, energy is gradually released and used to pump the hydrogen ions from the splitting of NADH and FADH<sub>2</sub> into the space between the inner membrane and the outer membrane (called the [[intermembrane space]]), creating an [[electrochemical gradient]].

This [[electrochemical gradient]] creates potential energy (see ''{{section link|potential energy|chemical potential energy}}'') across the inner mitochondrial membrane known as the [[proton-motive force]]. As a result, [[chemiosmosis]] occurs, and the enzyme [[ATP synthase]] produces [[Adenosine triphosphate|ATP]] from [[Adenosine diphosphate|ADP]] and a [[phosphate group]]. This harnesses the [[potential energy]] from the concentration gradient formed by the amount of H<sup>+</sup> ions. H<sup>+</sup> ions passively pass into the mitochondrial [[matrix (biology)|matrix]] by the ATP synthase, and later help to re-form H<sub>2</sub>O (water).

The [[electron transport chain]] requires a varying supply of electrons in order to properly function and generate ATP. However, the electrons that have entered the electron transport chain would eventually pile up like cars traveling down a blocked one-way street. Those electrons are finally accepted by [[oxygen]] (O<sub>2</sub>). As a result, they form two molecules of [[water]] (H<sub>2</sub>O). By accepting the electrons, oxygen allows the electron transport chain to continue functioning. The chain is organized in the cristae lumen membrane, i.e. the membrane inside the junction.<ref name=baker/>

The electrons from each NADH molecule can form a total of 3 ATP's from ADPs and phosphate groups through the electron transport chain, while each FADH<sub>2</sub> molecule can produce a total of 2 ATPs.

As a result, 10 NADH molecules (from [[glycolysis]] and the [[Krebs cycle]]), along with 2 FADH<sub>2</sub> molecules, can form a total of 34 ATPs during [[aerobic respiration]] (from a single electron transport chain). This means that combined with the Krebs Cycle and [[glycolysis]], the efficiency for the electron transport chain is about 65%, as compared to only 3.5% efficiency for glycolysis alone.