BIO315H5 Lecture 23: BIO315 - Lecture 23
Document Summary
Remove nutrients from cells in the s phase - won"t produce proper dna so it will arrest at the next checkpoint. Remove nutrients when cells in the m phase - cells arrest at next g1 phase. Mutate cyclin b (loss-of-function) - will have a problem transitioning from g2 to m phase. Dna replication can only occur once during cell cycle. In first step of dna replication (late m to early g1) - must make sites on dna permeable to replication. Helicases become active, unwind dna and begin replication. Yellow = pre-replicative complex at sites of ori. M phase - replicative dna is parcelled out into identical nuclei. Late mitosis to next g1 - drop in s and m cdk and rise in apc/c activity - allows the pre-rc to assemble again. Mechanism for 1 round of dna replication. Mcm (minichromosome maintenance proteins) helicases are deposited here to form pre- S-cdk stimulates assembly of initiator proteins on dna helicases.
