A runner walks for 3 minutes and then runs at a faster, steady pace for 3 minutes on a treadmill.

In a model of cellular respiration, one molecule of glucose reacts with six molecules of oxygen:

Use the model below and the drop down menus to complete the sentences about bond changes and energy transfer during cellular respiration in muscle cells.

During an intense workout, a student’s leg muscles receive less oxygen than at rest. A blood sample from the muscle during the workout shows:

Organisms carry out chemical reactions that either release energy by breaking down molecules, or store energy by building larger molecules.

Students use sealed respirometers to compare cellular respiration in germinating peas and dry peas at the same temperature.