...respiration!
Respiration is the biochemical process in which the cells of an organism obtain energy by combining oxygen and glucose, resulting in the release of carbon dioxide, water, and ATP (the currency of energy in cells). Source: https://study.com/academy/lesson/what-is-respiration-definition-process-equation.html
I hope that helps! :)
Reproductive system and it's functions
Power is the rate (energy amount per time period) at which work is done or energy converted.