How Cells Divide

Chapter 10

Bacterial Cell Division

• Binary Fission• FtsZ protein

Eukaryotic Chromosomes• Chromosome Numbers Vary• Made of Chromatin

Some Vocab

• Karyotype

• Haploid

• Diploid

• Homologue

• Chromatids

Overview of the Cell Cycle

• G1

• S

• G2

• M

• C

• G0

Interphase• G1, S, G2

Mitosis

• Prophase

• Prometaphase

• Metaphase

• Anaphase

• Telophase

Prophase

• Condensation of Chromosome Contintues

• Spindle apparatus– Asters

• Nuclear envelope disassembles

Prometaphase

• Micrtubules attach to the kinetochore

• Chromosomes begin to move toward the equator of the cell

Metaphase

• Chromosomes are aligned at the equator of the cell called the metaphase plate

• Chromosomes are attached to opposite poles and are under tension

Anaphase

• Proteins holding centromeres of sister chromatids are degraded, freeing individual chromosomes

• Chromosomes are pulled to opposite poles

• Spindle poles move apart

Telophase

• Chromosomes are clustered at opposite poles and decondense

• Nuclear envelopes reform around chromosomes

• Golgi complex and ER re-form

•

Cytokinesis

• Plant vs Animal

Control of the Cell Cycle

• Irreversible points

• Checkpoints

MPF

• Nondividing cells can be stimulated into division by MPF

• MPF activity changes throughout the cell cycle

• It is cyclin pluc cdc2 (aka Cdk)– What is a kinase?

Three main Checkpoints

• G1/S

• G2/M

• Spindle Checkpoint (APC)

• Figure 10.20

Growth Factors

• Trigger intracellular signaling systems

• RTKs and MAP cascades

G0 Phase

• Dormant

• Liver vs Intestinal Lining Cells

Cancer

• Tumor Suppressor genes- p53, Rb

• Oncognes-ProtoOncogenes