ATP, or adenosine triphosphate, is created during a process called oxidative phosphorylation. It happens when mitochondria convert food into energy. ATP is a cell’s main energy source.
ATP is found in all living cells and cells continuously break down ATP for energy. ATP fuels transmission of nerve impulses, muscle contractions, formation of nucleic acids and many other metabolic reactions. ATP molecules are made up of carbon, hydrogen, oxygen, nitrogen and phosphorus atoms.
ATP does not store energy, but when energy is needed, ATP delivers it to the places within the cell where energy is being consumed. ATP is a nucleotide made up of a nitrogenous base, ribose and a chain of three phosphate groups that are bound to the ribose. Energy is released when the phosphate bonds are broken by the addition of a water molecule. This process is called "hydrolysis."