Question

How is the eukaryotic cell cycle regulated? Include how cell cycle events are initiated and how progression of the cycle is regulated.

Answer 1

The cell cycle is an ordered series of events. it is the sequence of events by which a cell duplicate its genome and eventually divides into two daughter cells. Cell cycle is regulated by cyclin and cyclin dependent protein kinases.

the engines that drive the progression from one step of the cell cycle to the next are a series of protein complexes composed of two subunits: cyclin and cyclin dependent protein kinases (CDKs) .

Cyclin is a regulatory component whereas cyclin dependent kinase is catalytic and acts as protein kinase. Cyclins 800 named because they undergo a cycle of synthesis and degradation in each cell cycle.

In eukaryotes, there are four classes of cyclins, is Defined by the stage of the cell cycle at which the wind cyclin dependent kinases and function : G1 cyclin , G1/S cyclins , S cyclins , and M cyclins .

Cyclins binds to cyclin dependent kinases molecules ant control their ability to phosphorylate appropriate target proteins. Each cyclin is rapidly synthesized during a specific phase of the cell cycle and is again promptly broken down after it serves its purpose.

They are broken down not only because they are no longer needed, but also because the breakdown is required for the cell cycle to transition to the next step.