Week 11 - Cell Cycle

G1

Checkpoint 1 - growth + nutrients + health

Anabolism

Produce membranes - organelle

Produce proteins/pre initiation complex - replication

S

DNA replication

Duplicate centrosomes

G2

Checkpoint 2 - DNA errors/repair

Replenish energy stores

Produce proteins - mitotic spindle

Duplicate mitochondria

Prophase

Condense chromatin

Break down nuclear envelope/nucleolus

Form kinetochore

Microtubule organising centre

Kinetochore

Attachment point on centromere for mitotic spindle

Metaphase

Centrosomes at opposite poles

Chromosomes line up at metaphase plate

Sister chromatids attached to opposite

Anaphase

Cohesin cleaved by separase

Chromosomes pulled by motor proteins

Non-kinetochore spindle fibres lengthen + elongate cell

Cohesin

Protein binds sister chromatids together

Telophase

Decondense chromosomes

Form nuclear envelope/nucleolus

Break down mitotic spindle

Cytokinesis

Contractile actin ring form cleavage furrow

Constriction - pinch inwards

2 identical daughter cells

How to Visualise Cell Cycle - Process

Propidium iodide

Intercalate with DNA

Fluoresce

Intensity directly proportional to DNA