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.

The added information provided at pause points within the animation Coral Bleaching allows for a richer exploration of coral reefs, symbiosis, and other topics in biology.

This activity explores content presented in the animated video Solving Crimes with the Necrobiome, which describes the microbial changes associated with decomposing corpses.

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 multipart animation series explores the process of photosynthesis and the structures that carry it out.

This activity explores images of planarians regenerating missing body parts, which serve as phenomena for learning about cell division and differentiation.

This interactive module consists of a virtual Winogradsky column, which can be used to explore the diversity of microbes, microbial metabolic strategies, and geochemical gradients found in sediments.

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 guides the analysis of a published scientific figure from a study that used SNP genotyping to identify the mutations that result in morphological differences in stickleback fish.

This short video explores the stages of decomposition of animal bodies and shows how microorganisms found during the decomposition process can provide useful information for criminal investigators.