<P> In the kidneys , the enzyme AGAT catalyzes the conversion of two amino acids -- arginine and glycine -- into guanidinoacetate ( also called glycocyamine or GAA ) , which is then transported in the blood to the liver . A methyl group is added to GAA from the amino acid methionine by the enzyme GAMT , forming non-phosphorylated creatine . This is then dumped into the blood by the liver where it travels mainly to the muscle cells ( 95 % of the body 's creatine is in muscles ) , and to a lesser extent the brain , heart , and pancreas . Once inside the cells it is transformed into phosphocreatine by the enzyme complex creatine kinase , which makes it able to donate its phosphate group to convert adenosine diphosphate ( ADP ) into adenosine triphosphate ( ATP ) . This process is an important component of all vertebrates ' bioenergetic systems . For instance , while the human body only produces 250g of ATP daily , it recycles its entire body weight in ATP each day through creatine phosphate . </P>
where is creatine phosphate found in the body
muscle cells brain heart pancreas