1. How often should cells divide?
What would happen if not enough or too many cells were created?

2. 5.3 Cancer
NOTE:
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Reaves 16-17

3. Lesson Essential Question:
What causes cancer?

4. Internal and External Factors
External factors include physical and chemical signals.
Growth factors are proteins that stimulate cell division.
Most mammal cells form a single layer in a culture dish and stop
dividing once they touch other cells.
Internal factors can be triggered by external factors.
Kinases – an enzyme that transfers a phosphate group from molecule to a target molecule
Cyclins – a group of proteins that help advance the cell through the cell cycle

5. Cell division is uncontrolled in cancer.
Cancer is caused by uncontrolled cell division.
Cancer cells form disorganized clumps called tumors.
Benign tumors remain clustered and can be removed.
Malignant tumors metastasize, or break away, and can form more tumors.
What causes cancer? P146  YOW
(Include the word carcinogen)