AP BIOLOGY

Detailed explanation-1: -NADH dehydrogenase (complex I) is a protein composed of 42 subunits, 7 of which are encoded by the mitochondrial genome. Complex I transfers electrons to coenzyme Q10 after the electrons have passed through a series of redox groups, including FMN and six iron–sulfur clusters.

Detailed explanation-2: -Complex I (NADH dehydrogenase) is the first enzyme in the respiratory chain. It catalyses the electron transfer from NADH to ubiquinone that is associated with proton pumping out of the matrix.

Detailed explanation-3: -NADH is the electron donor for the electron transport chain. The first complex to accept the donated electrons is NADH dehydrogenase.

Detailed explanation-4: -Remember, NADH is a two-electron donor: it donates a hydride ion to a substrate, becoming NAD+. A hydride ion, of course, is just a proton and two electrons. NADH produced in glycolysis and the TCA cycle delivers a pair of electrons to Complex I.

Detailed explanation-5: -NADH carries the electrons gained from the breakdown of glucose and donates them to the chain of enzymes in mitochondria that are involved in producing ATP (electron transport chain). This oxidizes NADH back to NAD+.