AP BIOLOGY

Detailed explanation-1: -Pyruvate-three carbons-is converted to acetyl CoA, a two-carbon molecule attached to coenzyme A. A molecule of coenzyme A is a necessary reactant for this reaction, which releases a molecule of carbon dioxide and reduces a NAD+ to NADH.

Detailed explanation-2: -First, acetyl CoA combines with oxaloacetate, a four-carbon molecule, losing the CoA group and forming the six-carbon molecule citrate. After citrate undergoes a rearrangement step, it undergoes an oxidation reaction, transferring electrons to NAD+ to form NADH and releasing a molecule of carbon dioxide.

Detailed explanation-3: -Answer and Explanation: The stage of cellular respiration in which carbon dioxide release takes place is the citric acid cycle. Aerobic cellular respiration has three steps, glycolysis, the citric acid cycle and the electron transport chain.

Detailed explanation-4: -Products of Cellular Respiration During the transition reaction, the substrate pyruvate leads to the formation of the products CoA, NADH, and CO2. In the Krebs cycle, Acetyl CoA and oxaloacetate lead to the end products oxaloacetate, NADH, ATP, FADH2, and CO2.

Detailed explanation-5: -Breakdown of Pyruvate Upon entering the mitochondrial matrix, a multi-enzyme complex converts pyruvate into acetyl CoA. In the process, carbon dioxide is released and one molecule of NADH is formed.