Phosphorylation of a reactant in a pathway

• Phosphorylation is the process of adding a phosphate group to a reactant in a metabolic pathway.
• Phosphorylation is an enzyme-controlled process by which a phosphate group is added to a molecule.
• ATP is required for the phosphorylation of glucose and intermediates during the energy investment phase of glycolysis.
• This leads to the generation of more ATP during the energy pay-off stage and results in the net gain of ATP.
• In aerobic conditions pyruvate is then broken down to an acetyl group that combines with coenzyme A forming acetyl coenzyme A.
• For example, when low energy ADP and Pi combine to form high energy ATP.
• Similarly, if ATP donates a phosphate in a metabolic pathways to a reactant, the reactant becomes phosphorylated, and gains energy.