1. Section 10.3 (Pg. 286-290): Regulating the Cell Cycle

3. Controlling Cell Division
Uses proteins inside and outside the cell
Cyclins
Regulate the timing of the cell cycle
Internal regulators
Allow the cell cycle to proceed only when certain events have occurred

4. Controlling Cell Division
External regulators
Can speed up or slow down the cell cycle
Growth factors stimulate growth and division of cells
Other proteins can cause cells to stop dividing once they fill a space
Apoptosis
Is controlled cell death
Destroys malfunctioning cells
Can shape a growing embryo

5. Too Much Apoptosis

6. Cancer Cells do not respond to signals that regulate cell growth
Cells divide uncontrollably
These cells form a tumor
Benign tumors do not spread to healthy tissue
Malignant tumors take over and destroy healthy tissue
Metastasis
When cancer cells break off a tumor, travel to other parts of the body, and form more tumors

8. Causes of Cancer
Exposure to toxic chemicals, radiation, and some viruses
Results in defective or mutated DNA
Damage to genes that control cell growth can cause a tumor
Damage to the p53 gene is a common cause of many cancers

9. Treatment for Cancer Surgery Radiation Chemotherapy
Physically remove tumor
Radiation
Mutate tumor cells’ DNA to make them nonfunctional
Chemotherapy
Administer chemicals that kill tumor cells or slows their growth
Can also interfere with cell division in healthy cells, producing side effects