Cell cycle checkpoint regulation and intrinsic and extrinsic apoptosis pathways tested on USMLE Step 1.
35 cards · basic cards · AI-written, checked twice. Edit anything.
- What is the primary function of the G1 phase of the cell cycle?
Show answer
Cell growth and preparation for DNA synthesis.- What is the primary event of S phase in the cell cycle?
Show answer
DNA replication (chromosome duplication).- What is the primary function of G2 phase?
Show answer
Cell growth and quality control checks before mitosis.- What occurs during M phase of the cell cycle?
Show answer
Mitosis (nuclear division) and cytokinesis.- What is the G0 phase of the cell cycle?
Show answer
A quiescent state in which a cell has exited the cycle and is not actively dividing.- What is the restriction point (R point)?
Show answer
A late G1 checkpoint after which the cell is committed to divide independent of further growth signals.- What does the cyclin D-CDK4/6 complex do?
Show answer
Drives progression through G1 by phosphorylating the Rb protein.- What does the cyclin E-CDK2 complex promote?
Show answer
The transition from G1 to S phase.- What complex drives the transition from G2 to M phase?
Show answer
Cyclin B-CDK1, also called maturation-promoting factor (MPF).- What does hypophosphorylated (active) Rb protein do?
Show answer
Binds E2F and blocks transcription of genes needed for S phase.- What is the function of the E2F transcription factor?
Show answer
Drives transcription of genes needed for S phase entry once released from Rb.- What triggers activation of the p53 tumor suppressor protein?
Show answer
Detection of DNA damage in the cell.- What does p53 induce to halt the cell cycle at the G1/S checkpoint?
Show answer
p21, a cyclin-dependent kinase (CDK) inhibitor.- What does the G1/S checkpoint monitor?
Show answer
Whether DNA is undamaged before replication begins.- What does the G2/M checkpoint monitor?
Show answer
That DNA replication is complete and DNA is undamaged before mitosis begins.
FlashKeepers