BIO 3153 Lecture Notes - Lecture 3: Protein Kinase, Dna Replication, Molecular Switch
Document Summary
Focus on mechanisms of control that occur at specific stages. The cell cycle is a complex system of coordinated processes that must occur in a specific sequence. If performed incorrectly or out of sequence, results may be catastrophic. Regulatory proteins and biochemical switches control progression through the cell cycle. Allows cell to progress or pause when getting ready for the next stage. This system monitors intracellular and extracellular environments. Activity of cyclin (and thus cdks) rises and falls with cell cycle. Cyclins in all eukaryotes (4 major classes): Bind cdk near end of g1 and lead cell into dna replication. Cyclin concentration rises and falls before s phase. Bind cdk during s phase and are required for dna replication, control early mitotic events. Promote passage through restriction point in late g1. Take phosphate from atp and transfers that phosphate to a another protein leaving adp. Increase of m-cyclin causes them to bind to m-cdk, triggering mitosis.
