AP BIOLOGY

Detailed explanation-1: -In eukaryotes, the Krebs cycle reactions take place in the mitochondrial matrix, a dense solution that surrounds the mitochondria crests: in addition to water, the matrix contains all the enzymes necessary for the biochemical reactions of the cycle, coenzymes, and phosphates.

Detailed explanation-2: -In the mitochondrion, the matrix is the space within the inner membrane.

Detailed explanation-3: -The mitochondrial matrix has the required enzymes and environment for the complex reactions of the Krebs cycle to take place. Further, the products of the Krebs cycle drive the electron transport chain and oxidative phosphorylation, both of which occur in the inner mitochondrial membrane.

Detailed explanation-4: -Within the mitochondrion, the citric acid cycle occurs in the mitochondrial matrix, and oxidative metabolism occurs at the internal folded mitochondrial membranes (cristae).

Detailed explanation-5: -Where does the Krebs cycle take place? The TCA cycle was first observed in the muscle tissue of a pigeon. It takes place in all eukaryotic and prokaryotic cells. In eukaryotes, it occurs in the matrix of the mitochondrion.