AP BIOLOGY

Detailed explanation-1: -As you can see from Figure above, a mitochondrion has an inner and outer membrane. The space between the inner and outer membrane is called the intermembrane space. The space enclosed by the inner membrane is ca lled the matrix. The second stage of cellular respiration, the Krebs cycle, takes place in the matrix.

Detailed explanation-2: -The second stage of cellular respiration, called the Krebs cycle, takes place in the matrix of a mitochondrion.

Detailed explanation-3: -There are three main steps of cellular respiration: glycolysis, the citric acid cycle, and oxidative phosphorylation. Glycolysis takes place in the cytosol, the citric acid cycle occurs in the mitochondrial matrix, and oxidative phosphorylation occurs on the inner mitochondrial membrane.

Detailed explanation-4: -In the presence of oxygen, under aerobic conditions, pyruvate enters the mitochondria to proceed into the Krebs cycle. The second stage of cellular respiration is the transfer of the energy in pyruvate, which is the energy initially in glucose, into two energy carriers, NADH and FADH2.