CELL CYCLE QUIZ AAAAAA Flashcards
2 Reasons for the cell cycle
- Replace old/damaged cells
- Growth/development of organism
Purpose of G1 and its checkpoint
A big growth spurt, produces proteins necessary for later steps. It’s checkpoint searches for DNA damage, adequate size.
Purpose of G0
branches off of G1
cell exists the cell cycle and stops dividing
Purpose of synthesis
DNA replication occurs
Purpose of Gap 2 and its Checkpoint
The cell continues to grow and prepares for mitosis. Its checkpoint checks for DNA replication errors back in synthesis before entering mitosis
What is the purpose of mitosis and it’s checkpoint.
The cell divides its duplicated chromosomes and cytoplasm. The checkpoint during metaphase makes sure the spindle fibers are correctly attached to chromosomes.
Parts of the cell cycle in order:
G1 (with checkpoint)
G0 (optional)
Synthesis
G2 (with checkpoint)
Mitosis
Role of CDK and cyclin
Signal timing of each phase and serve as supervisors for various checkpoints.
Role of p53 enzyme
Enzyme that stops cell division if DNA is damaged. The cell will either repair itself or if the damage is too severe, trigger the cell to self-destruct (apoptosis)
How do tumors form?
Mutated DNA somehow alters CDK-cyclin/p53 and duplicates with genetic errors that lead to uncontrolled cell division, so the cell can’t stop dividing even if there is DNA damage.
What happens where there is too much CDK cyclin and when there is too little.
When there is too much CDK and cyclin, there is unregulated cell growth/cancer, but it is a positive regulator that pushes cell division to continue.
When there is too little, cell division will be slowed down or prevented
What happens if there is too much or too little p53
Too much p53 can cause excessive cell death, while too little p53 can slow down or prevent cell division.
