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 activity explores images of anole lizards subjected to strong winds, which serve as phenomena for learning about natural selection and the impacts of extreme climate events.

This activity guides the analysis of a published scientific figure from a study that investigated how anole lizards may adapt to extremely cold temperatures.

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 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 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.