Electron Transport Chain

proteins

transport proteins embedded in the cristae of the inner membrane

H+ concentration gradient

high conc. in the intermembrane space, low conc. in the matrix

Protein channels

1. NADH dehydrogenase
2. Cytochrome b-c complex
3. Cytochrome oxidase complex
4. ATP synthase

Steps

1. NADH brings electrons to ETC, passes a proton (H+) to **ubiquinone (Q)**
2. Q passes energy to the NADH dehydrogenase signaling it to open to allow H+ into the intermembrane space
3. Q keeps traveling to Cytochrome b-c to do the same
4. Q cannot travel further and passes the H+ to the Cytochrome C
5. Cyt C takes the H+ to the cytochrome oxidase complex, allowing the H+ into the intermembrane space
6. H+ leaves cyt c, binding to an oxygen creating a water molecule.
7. All three H+ pass through the ATP synthase, allowing ADP to be turned into ATP

FADH2 steps

1. FADH brings H+ to ubiquinone which travels to the Cytochrome b-c, signaling for it to open allowing an H+ molecule to pass from the matrix to the intermembrane space
2. H+ jumps to cytochrome C which travels to cytochrome oxidase, opening and moving H+ against the conc. gradient
3. the H+ leaves the Cytochrome C, binds to an oxygen molecule, creating water

NADH from glycolysis

As glycolysis takes place in the cytoplasm, the NADH cannot go to the ETC. the NADH is converted into FADH2 in order to pass into the matrix, therefore the NADH only creates 2 ATP, because its FADH2

Oxidative phosphorylation

Creation of ATP in the ETC, called ‘oxidative’ because its dependent on oxygen being present. (Cyt C cant drop off the h+ to turn into water, then the cyt c cant go back and pick up more, creating a backlog)