Glucose + Oxygen = Carbon Dioxide + Water + ATP

C₆H₁₂O₆ + 6 O₂ = 6 CO₂ + 6 H₂O + ATP

The last stage of cellular respiration produces the most ATP and is only possible because of the hydrogen concentration gradient, which, in return only exists due to the function of the ionic pumps powered by the electrons carried from the previous 3 stages.

Takes place in the cytoplasm, outside the mitochondria. Glucose is converted to pyruvate. The metabolic pathway in glycolysis is catalyzed by enzymes, which are found in the cytoplasm.

Glucose is partially oxidized and a small amount of ATP is produced; partial oxidization is achieved without the use of oxygen.

One glucose molecule is converted into two pyruvates. 2 ATP molecules are used but 4 are produced, so there is a net yield of 2 ATP molecules.

Two NAD+ are converted into two NADH + H+.

Pyruvate travels into the mitochondrial matrix from the cytoplasm.

The link reaction essentially prepares the pyruvate for the Krebs cycle.

Pyruvate than goes through oxidative decarboxylation, which is the combination of Decarboxylation and Oxidation, producing an acetyl group, which is accepted by an enzyme in the Krebs cycle.

The link reaction involves one decarboxylation and one oxidation. There are two more decarboxylation's and four more oxidations in the Krebs cycle.

Reduced NAD and FADH2 donate their electrons to electron carriers found in the inner membrane of the mitochondria. As the electrons are passed from carrier to carrier energy is utilized by proton pumps to transfer protons across the inner membrane from the matrix and into the inter-membrane space. The protons then flow through ATP Synthase down their concentration gradient providing the energy needed to make ATP.