Nucleus 2 Flashcards
Quiescent
Can proliferate, but are not currently
Terminally differentiated
Do not divide
Senescent
No more proliferation, will die soon
Longest and shortest cell cycle phases?
G1 longest, M shortest
MPF
Cyclin B + Cdk1.
Drives and increases during mitosis
G1 phase cyclins
Cyclin D with Cdk4/6
Cyclin E with Cdk2
S phase cyclins
Cyclin A and Cdk2
G2 cyclins
Cyclin A and Cdk1
Cdk activation steps
Cdk and cyclin bind. Both inhibitory and activating phosphate added. Phosphatase removes inhibitory phosphate
Asexual proliferation
Clonal
Amount of gametes made per cell cycle
4 spermatids, 1 ovum
Phases of prophase in meiosis 1
Leptotene Zygotene Pachytene Diplotene Diakinesis
Leptotene
Pairing of homologous chromosomes
Zygotene
Synaptonemal comped forms
Pachytene
Crossing over
Diplotene
Synaptonemal complex dissolves
Diakinesis
Nuclear envelope breaks down
Mitosis vs meiosis
Homologous chromosomes pair in meiosis. Meiosis makes unique haploid daughter cells.
Cell cycle checkpoint
G1 dna checkpoint S restriction checkpoint (pRB, p53) S dna checkpoint G2 checkpoint (BrCa 1/2) 2 more in M
Mitogens
Stimulate cell divisions, usually directly stimulate CDKs
Growth factors
Indirectly stimulate CDKs
pRB
Protein that inhibits E2F transcription factors that start G1/S. Inhibited by Cyclin D with Cdk4/6
Restriction point
G1/S phase checkpoint.
p53
Tumor suppressing protein. Dna damage activates, which then activated CDK inhibitors. Also initiates apoptosis
Apoptosis
Cell death. Stimulates by cytochrome c from mitochondria. Initiates capsize cascade.
Capase cascade
Apoptosis. Degrade dna, nuclear lamins, and cytoplasmic proteins.
Necrosis
Pathological cell death. Trauma, chemicals, lack of nutrients, viruses. Swelling until busting, affecting nearby cells.