Cell Cycle Flashcards
What are the three phases of interphase?
G1, S phase and G2
What is the G1 phase?
It is an intermediate phase where normal function of the cell occurs
What does the cell do in the G1 phase?
It makes sure that DNA can be replicated. It is where DNA is transcribed.
What is the S phase?
The S phase is where DNA is replicated
Why is it important to replicate DNA?
To allow each cell that is created to have the same genetic makeup
Once DNA replication is over, how many chromosomes will be found during S phase?
There will be 2 copies of chromosomes. 42 mom, 42 dad.
What else is replicated during the S phase?
Centrioles of the MTOC
When in S phase, what form is DNA in?
All the DNA becomes euchromatic
What is the purpose of the G2 phase?
It allows the cel to make sure it has all the right proteins for cell division
What happens if a cell does not pass a checkpoint in the G1 or G2 phase?
The cell will undergo apoptosis
Define: mitosis
The shorter phase of the cell cycle where the cell actually divides
What are the two major phases of the cell cycle?
Interphase and mitotic phase
Define: cell cycle
The two-phase cycle where a cell replicated it’s DNA, and then divides.
Define: cyclin
A protein that constantly goes through synthesis and degradation during the cell cycle
What happens when Cyclin is synthesized?
It activates CDK
During which of the cell cycle does copying take place?
During interphase
During which phase of he cell cycle does cleavage take place?
Mitosis
What is the name of the phase between the end of M phase and the beginning of S phase?
G1
What is the name of the phase between the end of S phase and beginning of M phase?
G2
Through phosphorylation, what does the Cdks signal?
It signals that the cel is ready to move to the next stage of the cell cycle
What does the cyclin-CDK complex do?
It acts as a signal to pass to the next cell cycle phase.
When Cyclin degrades, what happens?
It deactivates the CDK to signal exit from a phase
What is the name of the enzyme that digests Cyclin?
Cyclinase
What happens when the MPF (Cyclin-CDK complex) phosphorylates p53?
It enters the cell and tries to repair the DNA
What is another name for p53?
A tumor suppressant
What happens if p53 doesn’t shut down? If it does shut down?
If p53 doesn’t shut down apoptosis occurs. if it does shut down, S phase continues
_________ binds to Cdks to activate them. Once activated, Cdks signal progression through _____________.
Cyclin. Phosphorylation
