ATP- Adenosine Triphosphate

Composed of an adenine, a ribose, and 3 phosphate groups, an ATP molecule is the common currency for energy in the cell. When we eat food, we don't digest it to make energy directly. We digest it to create ATP, which we then use for energy.

The energy is stored in the bond between the 2nd and 3rd Phosphate group. Dephosphorylation (aka ATP Hydrolysis) occurs when the 3rd phosphate group detaches from the molecule, forming ADP (adenosine diphosphate) and an inorganic phosphate group. When that phosphate bond is broken, all the potential energy stored in the chemical bond is released and can power cellular processes like endocytosis, protein synthesis and DNA replication.

Our bodies are constantly using ATP so we need to constantly regenerate ATP. This is done through a process called Phosphorylation, and is done in the Mitochondria, in a process called Cellular Respiration.