Final answer:
Pyruvate oxidation and the citric acid cycle take place in the mitochondrial matrix. They are pivotal processes in cellular respiration, leading to the production of ATP, NADH, and FADH2, which are then used in oxidative phosphorylation.
Step-by-step explanation:
The oxidation of pyruvate and the citric acid cycle both occur in the mitochondrial matrix of eukaryotic cells. The pyruvate produced at the end of glycolysis is transported into the mitochondria, where it undergoes oxidation to form a two-carbon acetyl group. This acetyl group is then fed into the citric acid cycle, also known as the Krebs cycle.
The cycle is involved in a series of redox reactions that result in the production of high-energy electron carriers NADH and FADH2 in addition to ATP. The NADH and FADH2 then pass their electrons to the electron transport chain, which is located in the inner mitochondrial membrane, to continue the process of ATP production through oxidative phosphorylation.