Cell-cycle checkpoints

Definition

Cell-cycle checkpoints are regulatory pathways that ensure the proper progression of the cell cycle. They prevent the cycle from advancing to the next phase until specific conditions are met, ensuring genomic integrity and cellular function.

5 Must Know Facts For Your Next Test

1. The primary checkpoints in the cell cycle are the G1 checkpoint, G2 checkpoint, and M checkpoint.
2. The G1 checkpoint determines whether conditions are favorable for cell division and checks for DNA damage.
3. The G2 checkpoint ensures all DNA is replicated correctly and checks for DNA damage before entering mitosis.
4. The M checkpoint, also known as the spindle assembly checkpoint, ensures that all chromosomes are properly attached to the spindle fibers before proceeding with anaphase.
5. Checkpoint failure can lead to uncontrolled cell division, contributing to cancer development.

Review Questions

• What are the main functions of cell-cycle checkpoints?
• Which checkpoint is responsible for verifying proper chromosome attachment during mitosis?
• How can malfunctioning checkpoints contribute to disease?

Related terms

Cyclins:

Proteins that regulate different stages of the cell cycle by activating cyclin-dependent kinases (CDKs).

Cyclin-Dependent Kinases (CDKs): Enzymes that, when combined with cyclins, control progression through different phases of the cell cycle.

Apoptosis: Programmed cell death that occurs in response to severe cellular damage or stress, often regulated by cell-cycle checkpoints.