How Do We Get Energy? (Chemical Reactions): Crash Course Biology #26

Cells need energy to power the chemical reactions that keep their microscopic cities running, and most of that energy comes from a chemical called ATP. In this episode of Crash Course Biology, we’ll learn how our cells use energy, what an enzyme’s role is in chemical reactions, and what makes a reaction exergonic or endergonic. Chapters: Cellular Cities 00:00 What Is Energy? 1:18 The Laws of Thermodynamics 2:22 ATP 4:07 Chemical Reactions 6:42 Enzymes 9:13 Metabolic Pathways 11:04 Review & Credits 12:09 This series was produced in collaboration with HHMI BioInteractive, committed to empowering educators and inspiring students with engaging, accessible, and quality classroom resources. Visit for more information. Check out our Biology playlist here: Watch this series in Spanish on our Crash Course en Español channel here: