Protein kinase

A Protein Kinase is a very important group of proteins involved  in signal transduction within cells. Protein Kinases are a family of proteins which, when activated, phosphorylate other proteins or molecules. There are three main types of Protein Kinase known as Protein Kinase A, B and C. They are all very important in cell signaling and signal transduction as they cause a phosphorylation cascade which is required to amplify the secondary messenger. They are also very important in other biochemical pathways, for example protein kinase A is involved in the metabolism of glucose and glycogen metabolism.