MICROANATOMY

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 Kreb’s cycle, oxygen is indirectly needed whereas, in the ETS, oxygen is directly needed in order to act as the final electron acceptor in the flow of electrons through the system.

Detailed explanation-3: -The Krebs cycle occurs in the mitochondrion of a cell (see Figure 6-1). This sausage-shaped organelle possesses inner and outer membranes and, therefore, inner and outer compartments. The inner membrane is folded over itself many times; the folds are called cristae.