Creatine is formed mainly in the liver from the methylation of glycocyamine by S-adenosyl methionine. It is then carried through blood to the other organs, muscle, and brain, where, through phosphorylation, it becomes the high-energy compound phosphocreatine. Creatine transformation to phosphocreatine is activates by creatine kinase; spontaneous formation of creatinine produces throughout the reaction. As shown in (fig. 15)
Creatinine is removed