Ch.17-Cell Cycle and Programmed Cell Death Flashcards
- Describe the cell cycle including the different phases that occur during mitosis
G1»_space; S»_space; G2»_space; M (mitosis and cytokinesis)
- Mitosis: Prophase, metaphase, anaphase, telophase
2A. Describe the processes that occur during the G1 phase
= long resting phase; most cells in this stage
2B. Describe the processes that occur during the S phase
= DNA replication
2C. Describe the processes that occur during the G2 phase
= short resting phase, has 96 chromosomes
2D. Describe the processes that occur during the M phase
= mitosis (nuclear division), cytokinesis (cytoplasmic division)
3A. What are cyclin dependent kinases?
= protein kinases (enzymes that phosphorylates proteins) that need to bind to cyclin in order for it to be activated
3B. What is their role of cyclin dependent kinases in the cell cycle?
- Control the cell division cycle
- phosphorylates other proteins
- What are cyclins?
= The protein that controls whether Cdk are active
- List the different cyclins involved in the cell cycle and the processes they control.
- G1 cyclin
- G1/S cyclin
- S cyclin
- M cyclin
6A. What are Cdk inhibitory proteins?
= proteins that inactivate cyclin dependent kinases by binding to active Cdk
6B. What does p27 do?
= is a type of Cdk inhibitory protein
- How else can Cdk’s be inactivated?
- By inhibiting phosphorylation»_space;> phosphorylation twice = inactive
- Can be labeled with ubiquitin and degraded
8A. What is APC?
= Anaphase promoting complex; It is activated by M-Cdk
8B. What does APC do?
= Activates separase (cuts cohesive proteins); degrades M-cyclin, which deactivates M-Cdk
- How come a cell in G1 phase that has assembled the pre-replicative complex does not immediately go in to the S-phase?
A signal molecule is required??
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10A. Describe the role of cyclins G1 in moving a cell from the G1-phase to the S-phase.
- makes active Cdk complex that forms G1/Cdk;
- phosphorylates Rb protein;
- released more E2F;
- increase in G1/S and S cyclin
10B. Describe the role of cyclins G1/S in moving a cell from the G1-phase to the S-phase.
makes active G1/S Cdk