1.6 Cell Cycle and Cyclins

3 parts of Interphase

Growth phase 1, Synthesis phase, growth phase 2

5 parts of the Mitosis Phase

Prophase, metaphase, anaphase, telophase, cytokinesis

Growth 1 Phase

cell growth and normal cell function

Synthesis Phase

DNA replication

Growth 2 Phase

preparing for mitosis: duplication of organelles

Prophase

chromatin supercoils into chromosomes, nuclear membrane dissolves, formation of spindle fibres, centrosomes move towards the poles

Metaphase

chromosomes move towards the equator, spindle fibres attach to the chromosomes

Anaphase

sister chromatids are pulled apart towards opposite poles, movement is due to the shortening of the spindle fibres

Telophase

each end of the cell now has a complete set of identical chromosomes, nuclear envelope starts to reform, chromosomes uncoil into chromatin, spindle fibres disappear

Cytokinesis

the splitting of the cell immediately following mitosis

Cytokinesis in an Animal Cell

a contractile ring is formed around the outside and contracts pinching the cell into 2

Cytokinesis in a Plant Cell

forms a cell plate which grows until the two cells separate

Order of Cyclins

D, E, A, B (don’t eat a baby)

Cyclins

proteins that regulate the cell cycle

How do cyclins control the cell cycle

cyclins bind to enzymes called cyclin-dependent kinases. They cause phosphate groups to attach to other proteins. This attachment triggers them to regulate the cell cycle

Which cyclin regulates which phase?

D=Growth 1

E=Synthesis Phase

A=Growth 2

B=Mitosis