cell cycle

purpose of G1?

growth and preparation for DNA synthesis

purpose of S phase?

DNA replication

G2 purpose?

organelle replication

what is G0?

cell exits cell cycle

how are the stages of mitosis defined?

by chromosome behaviour

2 main purposes of the cell cycle

faithful DNA duplication, accurate DNA segregation

what protein complexes are responsible for controlling cell cycle checkpoints?

cyclin-CDKs

what are the 3 main checkpoints?

G1/S (R point), G2/M, metaphase-to-anaphase transition

why are checkpoints important?

ensures key tasks (DNA replication/segregation) have been completed

which cyclin-CDK complexes are responsible for activating the G1/S checkpoint?

cyclin D-CDK4/6 (cyclin E-CKD2 produces signals later)

how does cyclin D-CDK4/6 regulate cell cycle progression?

the complex will phosphorylate Rb but not enough to activate transcription factors E2F and DP

how does cyclin E-CDK2 regulate G1/S and aid cell cycle progression?

cyclin E-CDK2 will hyperphosphorylate Rb that will activate E2F and DP to transcribe genes such as