section 10.3 (pg. 286-290): regulating the cell cycle
TRANSCRIPT
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
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
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
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
Treatment for Cancer - Surgery
– 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