Basis of differentiation | Kinases | Phosphorylases |
Definition | Kinases refer to enzymes that catalyze the transfer of a phosphate group from ATP or GTP to its protein substrates | Phosphorylases refer to enzymes which catalyze phosphorylation through inorganic phosphates |
Addition of phosphate groups | Kinases add phosphate groups to existing organic molecules (does not break the bonds in the substrate) | Addition of phosphate groups by phosphorylases break bonds in the substrate |
Regulation | Regulated by phosphorylation | Regulated by phosphorylation or allosteric regulation |
Co-substrate requirement | Uses a phosphate group from ATP or GTP for phosphorylation reactions | Uses inorganic phosphate groups as the donor of phosphate groups for the formation of a phosphorylated intermediate |
Substrate specificity | Kinases typically phosphorylates specific target molecules (e.g. proteins, lipids, carbohydrates) | Phosphorylases specifically phosphorylate glycogen or other similar polysaccharides |
Functions | Kinases play a vital role in cellular signaling, metabolism, cell division and gene expression | Phosphorylases are involved in regulation of energy metabolism (specifically glycogen breakdown) |