Just watch Science take place.
Clipart from: http://www.clipartbest.com/clipart-McLkq5ani Mitochondria picture is from: https://simple.wikipedia.org/wiki/Mitochondria Respiration formula from: http://study.com/academy/lesson/what-is-respiration-definition-process-equation.html Scratch cat movement from: https://scratch.mit.edu/projects/76177208/ Everything else by me.
