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.
This interactive module allows students and educators to build models that explain how the Earth system works. The Click & Learn can be used to show how Earth is affected by human activities and natural phenomena.
This animation shows how mutations in an ion channel protein lead to the genetic disease cystic fibrosis. The animation also discusses how research on this protein has been used to develop treatments for the disease.
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.
This animated short video celebrates the early 20th-century German astronomer and atmospheric scientist Alfred Wegener, who first proposed that continents once formed a single landmass and had drifted apart.