This Video explores the process of how living things make and use energy. Cellular respiration is the process which takes energy from what we eat, breaking it down during metabolic reactions into glucose for use in energy production.
The Body stores this energy for future use as ATP (Adenosine Triphosphate) molecules. ATP is a marvelous molecule allowing organisms to move, grow, create brain signals and perform essentially any kind of activity.
Oxygen is vital for mass ATP production, known as aerobic respiration, and without ATP the body has no energy. This video explores the discovery of ATP, the different ways our body makes it and the processes involved along the way.
From Crash Course: Biology on YouTube by Hank Green.