AP BIOLOGY

Detailed explanation-1: -NAD+ reduction to NADH is featured in glycolysis, pyruvate dehydrogenase, and the tricarboxylic acid cycle (TCA cycle). NADH oxidation to NAD+ occurs in the cytoplasm by action of lactate dehydrogenase and in mitochondria by action of Complex I.

Detailed explanation-2: -When NAD+ takes an electron from glucose, it becomes NADH, the reduced form of the molecule. NADH transports this electron to mitochondria where the cell can take the energy that is stored in the electron. NADH then donates the electron to oxygen, converting it back to NAD+.

Detailed explanation-3: -The conversion of NAD from its oxidized form (NAD+) to its reduced form (NADH), and back, provides the cell with a mechanism for accepting and donating electrons. NAD+/NADH plays a significant role in the reactions associated with glycolysis, oxidative phosphorylation, and fermentation.

Detailed explanation-4: -Oxidation and Reduction Reduction is when a molecule gains electrons, such as when NAD+ gains the electrons from a hydride to become NADH. In this case, we say that NAD+ has been reduced to NADH. Oxidation is when a molecule loses electrons, such as when NADH loses its hydride to become NAD+.

Detailed explanation-5: -Alcohol Dehydrogenase This is an oxidation reaction and results in the removal of two hydrogen ions and two electrons which are added to the NAD+, converting it to NADH and H+. This is the first reaction in the metabolism of alcohol. The active site of ADH has two binding regions.