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: -The Krebs cycle happens only within the mitochondrial matrix. Pyruvate is formed in the cytosol of the cell, then imported into the mitochondria. Here, it is converted to acetyl CoA and imported into the mitochondrial matrix.

Detailed explanation-3: -Krebs’ cycle Enzymes within the mitochondria matrix are designed to oxidize the substrates within, in a cyclic manner. That is, every product of a reaction is a potential substrate for another reaction. The most reduced of the substrates (greatest available free energy) is citric acid (citrate).

Detailed explanation-4: -In the mitochondrion, the matrix is the space within the inner membrane.