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Unformatted text preview: romosome thickens,
nucleus of G1 phase cell, enters M phase
What happens when a S PHASE cell is fused to a G 1 PHASE cell ? G phase cell begins replicating its DNA (enters S phase)
What happens when a S PHASE cell is fused to a G2 PHASE cell ? chromosomes in G2 phase cell do not replicate
do not enter S phase sucks out cytoplasm inserts into different cell
MICROINJECTION EXPERIMENTS (MARKERT & MASUI EXPERIMENTS) :
What happens when M PHASE cytoplasm is injected into a G 2 PHASE cell ? G phase cell begins M phase
What happens when INTERPHASE cytoplasm is injected into G 2 PHASE cell ? G2 phase cells remain in G2 phase
What do the aforementioned experimental observations suggest? 1 regulatory molecules control entry into M and S phases
2 Molecular signals in cytoplasm of M phase cells initiate
Fig. 11.14 M-Phase Promoting Factor is Created When a Cyclin Binds to a Protein Kinase
CELL CYCLE ENZYMES
CYCLINS increase and decrease in concentration - proteins that oscillate in concentration during the cell cycle and regulate cyclin dependent kinase activity
MPF (Mitosis promoting factor) MPF - mitotic promoting factor - MPF is present in the cytoplasm and consists of two components: a protein kinase (cyclin -dependent kinase),
which catalyzes the phosphorylation of a protein, and a cyclin
Cdk (CYCLIN DEPENDENT KINASE) kinase adds phosphates - protein kinase, which uses ATP
- adds phosphate group to protein
- induces a conformational change
- to be active it must be att...
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This note was uploaded on 10/14/2012 for the course ASTRO 1f03 taught by Professor Perkins during the Spring '12 term at McMaster University.
- Spring '12