This animation shows the reactions of the citric acid cycle, which splits off carbon atoms and generates energy-rich reduced forms of cofactor molecules. It is the first of three animations about cellular respiration.
This animation shows how the enzyme complexes of the electron transport chain harvest energy from cofactor molecules to pump protons across the mitochondrial membrane and establish a chemical gradient. It is the second of three animations about cellular respiration.
A number of questions are embedded within the short film The Making of the Fittest: The Birth and Death of Genes, which illustrates how gene duplications and mutations have led to remarkable physiological adaptations in Antarctic fish.