Intro to cell cycle? Flashcards
What are the two main parts of cell cycle?
Interphase and mitosis
What is the interphase stage? And what phases is it made up of? What is the purpose of each stage?
It’s when chromosomes prepare for duplication and duplicate. G1,S,G2.
G1-growth and metabolic roles
S-chromosome duplication
growth and prepration for mitosis
What is the fastest stage in the cell cycle?
Mitosis
What are the periods found in mitosis and what is the purpose of each?
Prophase-The chromosomes will condense
Metaphase-The chromosomes will attach to spindles and move toward the center of the cell
Anaphase- Sister chromatids will seperate
Telophase- The chromosomes will decondense
What is cytokinesis?
Physical seperation of divided cells
When are cell in G0? What is G0?
The resting phase
Differntiated or deprived of nutirents
What is the purpose of checkponts and control in cell cycle?
To ensure that the cells divided with no errors and they are diploid
Who was awarded noble prize for discovering control mechanism in cell cycle? What are the conclusions of cell fusion experiments?
Hartwell, nurse, Hunt.
MPF contains factors that can induce chromosome condensation at any cell stage
But SPF has factors that only induce replication in G1 phase
What proteins are involved in controlling cell cycle?
CDK and cyclins
What period are cells sensitive to mitogens?
G1
How many cyclins, CDK, CDKI were identified in mammals?
13 cyclins, 8CDK,7CDKI
T/F
Cyclins and CDK the only proteins that change in the cell cycle
False
T/F
Cyclin D is cell type specific
True
How are cyclins turned off?
By ubiquination and degradation
What genes transcribe Cyclin D? And what CDK do they bind to? What stage of the cell cycle are they expressed?
AP-1, c-myc, NFKB.
cdk4,2,6,5
Early stages G0,G1, peaks near the end of G1
What do cyclinD/CDK4 act on and what does it induce? What is it’s effect in the cell cycle?
RB, it phosphorylates RB which releases it from E2 phase, it induces th eprogression of the cell to S phase and through the restriction point
When is cyclinE/CDK 2 expressed? And what is it’s effect in the cell cycle?
At the end of G1 and degrades 1/2 way through Sphase
T/F
cyclinE/CDK 2 has histone kinase activity
T
When is cyclin A expressed and when does it degrade? What does it bind to? Why is it important in the cell cycle?
At the end of Sp phase, at anaphase
CDK2,1
Initiation and progression of replication
When is cyclin B expressed and when does it degrade? What does it bind to? Why is it important in the cell cycle?
end of S phase, end of anaphase
binds to CDK
Needed for cell to enter mitosis
Give an example of phosphatase? When does it accumulate?
CDC25, M phase
What role does phosphorylation play in CDK and cyclin during cell cycle
It activates and inactivates activity and it’s important for nuclear localization
What is CDC 13 and what is it’s role?
It’s a type of cyclin B important in cell cycle control prevents the cell from moving from g2 to m phase
What brings the cyclins to their CDKS?
chaperone complex
