Here is a great cell respiration resource for AP Biology. It's a 2-page handout with cards that sequence glycolysis, pyruvate conversion to Acetyl CoA, Krebs Cycle, Electron Transport Chain, and Chemiosmosis. Students take the events of cell respiration and add of breathing, eating, making ATP, and exhaling carbon dioxide. They can use the cards to set up an essay, or as a fun class cut-and-paste activity, or simply as a study aid. Students will love to stretch out the 16 cards on the floor or a long table and talk about aerobic cellular respiration.