Problem 8

Cyclin-dependent kinase (CDK) belongs to a family of protein kinases that have an important role in cell cycle and cell cycle regulation. The CDK can modify different proteins and substrates involved in the cell cycle. Mainly, they can add phosphate groups to their substrates and transfer them to form ATP molecules. CDKs has serine/threonine bases, are inactive in their monomeric forms, and require the binding of subunits for their activation. The activity of CDKs is well regulated in a cell cycle. Controlling the levels of cyclins, inhibitory and activating phosphorylation is another mechanism are some of its methods. The later mentioned method involves adding a phosphate group to the threonine and residues.