Cell Cycle - Pfeffer Flashcards
What is the typical cell cycle?
G1->S->G2->M then starts with G1 again.
What is the most variable part of the cell cycle?
G1 phase anywhere from 6-12 hours.
What are examples of permanent cells?
neurons and fat cells.
What type of cells are liver cells? (permanent, stable, or labile)?
stable
What happens if cell is not ready to move on during the G1 phase?
rate of cell proliferation of most mammalian cells is regulated through G1 transit. If not ready, cell will go into a ‘sleep’ phase called G0 with a stepdown of RNA and protein synthesis. If under severe stress, will undergo apoptosis.
What is the S phase?
initiation of DNA synthesis with euchromatin first and then heterochromatin. Synthesis of key proteins like histones and enzymes for DNA replication.
What happens during the G2 phase?
synthesis of proteins required for mitosis
What happens during the M phase?
Almost no RNA synthesis. Mitosis occurs.
What is the Hayflick number?
How many times cells can divide. Inversely related to age capacity.
What is progeria?
disease that only allows cells to divide a few times. Cause premature aging.
What is senescence?
state when cells can no longer divide. They begin to slow down in their production of proteins and RNA. They eventually die and the progeny is ended.
What is MPF?
maturation promoting factor. Have high levels when cells undergo mitosis.
What is the Wee1?
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What is p27 inhibitory protein?
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What is APC?
targets cohesins for degradation as well as CDK complexes.
Look at checkpoint summary slide at end of lecture.
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