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 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.
In this activity, students build a paper model of DNA and use their model to explore key structural features of the DNA double helix. This activity can be used to complement the short film The Double Helix.
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.
This activity extends concepts covered in the film The Origin of Birds. Students analyze and interpret data from a scientific paper to explore thermoregulation in living and extinct animals, including dinosaurs.
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.