Question

the diagram below represents protein complexes in the electron transport chain. drag and drop the correct label to show which molecules interact with complex i, ii, and iv. not all options will be used.
inner mitochondrial membrane
complex ii complex i complex iii complex iv
nadh 2h+
fadh₂ nad+ fad 1/2 o₂ gtp acetyl coa h₂o

Explanation:

• Complex I: NADH donates electrons to Complex I. As electrons pass through Complex I, NADH is oxidized to \(NAD^+\).
• Complex IV: In Complex IV, oxygen (\(\frac{1}{2}O_2\)) acts as the final electron acceptor. It combines with electrons and protons (\(2H^+\)) to form water (\(H_2O\)).

Answer:

• Complex I: \(NAD^+\)
• Complex IV: \(\frac{1}{2}O_2\) (for electron - accepting) and \(H_2O\) (as a product of the reaction at Complex IV)