It separates the contents of the mitochondrion from the rest of the cell, creating ideal conditions for aerobic respiration.

Metabolically active cells, like muscles and liver cells, require more energy, so they have more mitochondria for increased ATP production.

Cristae are the folds in the inner membrane of mitochondria, increasing the total surface area available for oxidative phosphorylation.

The inner mitochondrial membrane contains the proteins involved in oxidative phosphorylation, such as those necessary for the electron transport chain and enzymes like ATP synthase.

The matrix is the site of the link reaction and the Krebs cycle.

It contains the enzymes needed for these reactions, and also contains mitochondrial DNA.

Mitochondria are the site of aerobic cellular respiration.

Protons are pumped into the intermembrane space during oxidative phosphorylation.

The intermembrane space is small, so the concentration gradient between the intermembrane space and the mitochondrial matrix builds up quickly.

Mitochondrial DNA is used to synthesise some of the proteins required for the mitochondrion to function.