ATP means adenosine triphosphate. It consists of carbon, hydrogen, nitrogen, oxygen, and phorphorus, with the formula C10H16N5O13P3. Structurally it is a nucleoside made up of adenine (a nucleobase) and a ribose sugar molecule, with three phosphate groups. It transfers a phosphate group to another molecule to phosphorylate it (give it energy to get the bonds into a transition state).
If a person is "sterile", this means that they cannot reproduce. The word "sterilized" is essentially stating that there is no productive activity in order to be able to reproduce.
