Cell cycle checkpoints and regulation

Cell cycle

Cell cycle has 3 states (quiescent, interphase, mitosis), 5 phases (G0, G1, S, G2, M):

Quiescent/senescent state: G0 phase. Examples: neurons, cardiac muscle, RBCs

Interphase state: G1, S, and G2 phases
M (Mitosis) state: M phase — PMAT (prophase, metaphase, anaphase, telophase) occur during this phase.

3 major cell cycle checkpoints:
1. The end of G1
2. The end of G2
3. During metaphase of M