Question

Regarding the electron transport chain (ETC)...How many ATPs are produced from one NADH? From one FADH₂? Where in the ETC (i.e. to which electron carrier) does each of these molecules donate its electrons?

Answer 1

Q. Regarding the electron transport chain (ETC)...How many ATPs are produced from one NADH? From one FADH₂? Where in the ETC (i.e. to which electron carrier) does each of these molecules donate its electrons?

Answer: The ATP are formed by two way when one molecule of glucose is oxidized

1) 10% ATP formed through substrate level phosphorylation by directly ADP to ATP transfer of phosphate.

2) 90% ATP formed through oxidative phosphorylation by ATP synthase via proton gradient. These energy conserved in the form of chemical bond as NADH and FADH_2.

The one NADH produced 3 ATP and one FADH₂ produced 2ATP through proton gradient in electron transport chain (ETC).

In ETC, NADH and FADH2 indirectly electron transfer to O₂ molecule and formed H₂ O. These electron first accepted coenzyme Q and Q electron transfer to cytochrome C and finally electron accepted by  O₂ molecule and combined with it and formed water molecule.   The proton transfer to ATP synthase and formed ATP. These above process completed in inner membrane of mitochondria through electron transport system. These above process is called chemiosmosis.

ATP synthase consist of two sub domain that is F₀ membrane bound complex and F₁ complex composed of catalytic head and stalk.