Some beetles roll the flesh of dead animals into a ball and cover it in goop — all to feed their future offspring. Now scientists think that goo might do more than just slow decay. It also appears to hide the scent of the decomposing bounty and boosts another odor that repels competitors.
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 fourth of six animations about cellular respiration.
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 third of six animations about cellular respiration.