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.

In this activity, students learn about the factors that regulate the population sizes of wildebeest and buffalo in Serengeti National Park.

It is rare for a single phenomenon to span a large range of concepts. In this Educator Voices article, professor Holly Basta explains how to utilize our sickle cell resources to teach a variety of topics including the central dogma, gene therapy, Mendelian genetics, and evolution

For centuries, scientists have obsessed over a primordial blob that can shape-shift, clone itself, and live indefinitely.

In order to develop complex scientific explanations, students need to have many opportunities to grapple with a concept. In this Educator Voices article, hear how Amy Fassler uses a sequence of resources in a process called “curriculum spiraling.”

The world cut its daily carbon dioxide emissions by 17% at the peak of the pandemic shutdown last month, a new study found.

This film explores how life recovered after an asteroid wiped out the dinosaurs and how those events shaped the diversity of plants and mammals on Earth today.

For the first time, a blood test has been shown to help detect many types of cancer in a study of thousands of people with no history or symptoms of the disease.

To give rivers more room to sprawl, cities are keeping adjacent lands for limited uses such as parks that can flood when rivers rise.

An unplanned grand experiment is changing Earth. As people across the globe stay home to stop the spread of the new coronavirus, the air has cleaned up, albeit temporarily.