This animation shows how the proton gradient across the mitochondrial membrane powers the ATP synthase enzyme to make ATP. It is the third 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 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 multipart animation series explores the process of photosynthesis and the structures that carry it out.

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 video follows scientists working in Bangladesh as they test fruit bat populations to determine whether they are infected with Nipah virus, a potentially deadly human pathogen.

This film explores how the genetic and anatomical legacy of a fish can be seen today in the human body.

This film explores what our hair, teeth, and hearing reveal about our evolution from ancient reptilian ancestors.

This video provides an overview of the types of genes that, when mutated, can lead to the development of cancer.

This video shows the reactions of first-grade students to a replica of a Tiktaalik fossil.

This animation shows how a region of the brain called the cerebral cortex develops in a human fetus.

This animation shows how genes associated with autism affect the structure and function of neuronal synapses.