AP BIOLOGY

Detailed explanation-1: -The ETC is a collection of proteins bound to the inner mitochondrial membrane and organic molecules, which electrons pass through in a series of redox reactions, and release energy. The energy released forms a proton gradient, which is used in chemiosmosis to make a large amount of ATP by the protein ATP-synthase.

Detailed explanation-2: -Fuel for the Krebs cycle comes from lipids (fats) and carbohydrates, which both produce the molecule acetyl coenzyme-A (acetyl-CoA). This acetyl-CoA reacts in the first step of the eight step sequence of reactions that comprise the Krebs cycle, all of which occur inside mitochondria of eukaryotic cells.

Detailed explanation-3: -The Krebs cycle has two types of energy-carrying electron carriers: NAD+ and FAD. The transfer of electrons to FAD during the Kreb’s Cycle produces a molecule of FADH2. Carbon dioxide is also released as a waste product of these reactions.

Detailed explanation-4: -Glycolysis produces two ATP molecules, and the Krebs cycle produces two more. Electron transport begins with several molecules of NADH and FADH2 from the Krebs cycle and transfers their energy into as many as 34 more ATP molecules.

Detailed explanation-5: -In general, the main energy source for cellular metabolism is glucose, which is catabolized in the three subsequent processes-glycolysis, tricarboxylic acid cycle (TCA or Krebs cycle), and finally oxidative phosphorylation-to produce ATP.