Cell Cycle Flashcards
what are the 4 main checkpoints?
G1/S, S, G2/M, and mitotic spindle checkpoint
what is being looked for in the G1/S checkpoint?
A large healthy cell with generous stores of materials
What is being checked at the G2/M checkpoint? (3)
replication of all the organelles,
The DNA has all been replicated,
The DNA is not damaged
If a cell is stopped at one of the checkpoints and the cell has damaged or incomplete components, what are the two options?
The cell can be put in a holding stage, where it is given time to fix up, or apoptosis occurs
what is responsible for allowing a cell to pass a checkpoint?
the correct concentration of cyclins bound to cdk
how are cyclins and cdks produced?
growth factors that initate transcription and translation of there genes
how does each checkpoint of the cell cycle differ in terms of cyclin
each check point uses a different cyclin and cdk
Once the checkpoint is passed, what happens to the cyclin and cdk?
the cyclin is degraded but the cyclin dependent kinase is retained
Instead of cyclin in the M-Phase, what is used instead as a controller?
kineticore microtubules, since they check that they are connected to all the chromsomes
what occurs during prometaphase?
the nuclear envelope breaks down and the centrosomes grow bundles of microtubules that migrate to opposite poles
Define centromere, centrosome, and centriole
Centromre: the point at which a chromosome is attached to a spindle fiber
Centrosome: the centre from which microtubules emerge
Centriole: two of them at perpendicular angles make up a centrosome
Describe the function of P53
It is responsible for determining whether a cell goes into G0 or goes to apoptosis
What substance can P53 activate in light of G0?
micro RNA
what is the kinetochore?
It is a protein complex that acts as a “hook” that connects the centromere to the dyenin motor protein
what does the kinetochore do in terms of the microtubules?
It disassembles them as it passes over them
