BIOL130 Lecture Notes - Lecture 19: Spindle Apparatus, Restriction Point, Dna Replication
1 Aug 2016
School
Department
Course
Professor
Document Summary
Depends on cell type, developmental stage, external signals: some cells divide continuously at high rate, epithelial linings of intestine couple times per day. Some cells do not divide at all once (mature) - ex. neurons. Some cells become terminally-differentiated (highly specialized) and can no longer divide. Early embryos divide more quickly (g1 phase skipped or reduced: invertebrate 20-30 minutes, mammalian - ~13 hours. Not active unless bound to cyclin partner. Levels are constant: cyclin regulatory subunit (determines whether its on or off) How does m-cdk activity and cyclin concentration vary throughout the cell cycle. Concentration of the cyclin should go up high activity of mitosis. Should be high if a cell is going through mitosis. Cyclin depedant kinase and partner which drive the cell through all the phases of the cell cycle. S-cdk should be high when trying to push dna synthesis. M-cdk (mpdf)- should be sky high when pushing a cell through mitosis.
