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.
Several questions are embedded within the short film The Day the Mesozoic Died, which tells the story of the scientific quest to explain one of the greatest, long-standing scientific mysteries: the sudden disappearance of the dinosaurs at the end of the Cretaceous period.