Glycolysis enzymes are located in the cytosol of cells. Pyruvate enters the mitochondrion to be metabolized further. The mitochondrial matrix contains Pyruvate Dehydrogenase and enzymes of Krebs Cycle, plus other pathways such as fatty acid oxidation. The mitochondrial outer membrane contains large VDAC channels, similar to bacterial porin channels, making the outer membrane leaky to ions and small molecules. The inner membrane is the major permeability barrier of the mitochondrion. It contains various transport catalysts, including a carrier protein that allows pyruvate to enter the matrix. It is highly convoluted, with infoldings called cristae. Embedded in the inner membrane are constituents of the respiratory chain and ATP Synthase.
Pyruvate Dehydrogenase catalyzes oxidative decarboxylation of pyruvate, to form acetyl-CoA. The overall reaction is shown at right. The inner core of the mammalian Pyruvate Dehydrogenase complex is an icosahedral structure consisting of 60 copies of E2. Cycle of Krebs.
Pyruvate Dehydrogenase catalyzes oxidative decarboxylation of pyruvate, to form acetyl-CoA. The overall reaction is shown at right. The inner core of the mammalian Pyruvate Dehydrogenase complex is an icosahedral structure consisting of 60 copies of E2. Cycle of Krebs.
