AP BIOLOGY

Detailed explanation-1: -A carboxyl group is removed from pyruvate and released as carbon dioxide. The two-carbon molecule from the first step is oxidized, and NAD+ accepts the electrons to form NADH. The oxidized two-carbon molecule, an acetyl group, is attached to Coenzyme A to form acetyl CoA.

Detailed explanation-2: -The pyruvate dehydrogenase (PDH) enzyme is part of the multienzyme PDC, which catalyzes the physiologically irreversible decarboxylation of pyruvate to acetyl-CoA and is often referred to as a ‘gatekeeper’ in the oxidation of carbohydrate (Figure 3).

Detailed explanation-3: -In mitochondria, pyruvate will be transformed into a two-carbon acetyl group (by removing a molecule of carbon dioxide) that will be picked up by a carrier compound called coenzyme A (CoA), which is made from vitamin B5. The resulting compound is called acetyl CoA.

Detailed explanation-4: -carbon dioxide. The carbon dioxide is removed from pyruate during it’s conversion into an acetyl group.

Detailed explanation-5: -A carboxyl group is removed from pyruvate, releasing a molecule of carbon dioxide into the surrounding medium. The result of this step is a two-carbon hydroxyethyl group bound to the enzyme, pyruvate dehydrogenase.