Cell Division Flashcards
(13 cards)
what molecules regulate the cell cycle
cyclins
cyclin-dependent Kinases
cyclin dependent kinase inhibitors
where are there cell cycle checkpoints?
End of G1 (checking for DNA errors before synthesis begins)
before M (is DNA replicated properly, is env favourable)
at end of M (are all chromosomes attached to the spindle properly)
what happens if errors are found at the checkpoints
cell is directed for DNA repair, senescence or apoptosis
What do cyclins do?
Cyclin proteins bind to CDKs and regulate their ability to phosphorylate other proteins that control cell division/cycle
what molecules need to have an exquisite balance for the checkpoints to work
CKDs and CKDIs
what happens to different cyclin concentrations throughout the cell cycle
rise as they are needed and then decrease
what does CKD do
allows cell to progress through the cell cycle
what does CKDI do
stops progression of the cell through the cell cycle
What is P53
“guardian of the genome”. Can block the progression of the cell cycle at S phase, therefore a tumour suppressor gene.
what is the most common gene mutation in cancers
P53
what does P53 do?
synthesises P21 (an inhibitor) which inhibits CKD2
WHat is retinoblastoma?
rare cancer of the immature cells of the retina
most common in young children
What is Rb protein
tumour suppressor gene
prevents DNA synthesis and replication
