Cellular respiration is the process that releases energy from glucose in the presence of oxygen. It involves three main stages: glycolysis, the Krebs cycle, and the electron transport chain. Glycolysis breaks down glucose and produces a small amount of ATP. The Krebs cycle further breaks down the products of glycolysis and produces more ATP and electron carriers. During the electron transport chain, electrons are passed along a chain which pumps hydrogen ions across a membrane. This creates a proton gradient that is used by ATP synthase to produce large amounts of ATP from ADP and phosphate. The overall equation is that glucose and oxygen are broken down to produce carbon dioxide, water, and a large amount of ATP as energy.
![[object Object],[object Object],1. How does your body feel at the start of exercise, such as a long, slow run? How do you feel 1 minute into the run; 10 minutes into the run? 2. What do you think is happening in your cells to cause the changes in how you feel? 3. Think about running as fast as you can for 100 meters. Could you keep up this pace for a much longer distance? Explain your answer.](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)