1. 10-3 Regulating the Cell Cycle

2. I. Controls on Cell Division

3. Cells divide at different rates
Nerve cells usually stop dividing once developed
Skin & bone cells grow & divide rapidly throughout life

4. Contact Inhibition Cells divide until they touch each other
Once the cells come in contact w/ each other they stop dividing
This is a way to control cell division
Controls on cell growth & division can be turned on and off.

5. Cells continue to grow until they come in contact w/ each other
Cells can be removed to regenerate cell division
Cells divide until they touch

6. Cell Cycle Regulators

7. Cyclins- a protein that determines the timing of the cell cycle
The amount of cyclin rises & falls in time w/ the cell cycle

8. Cyclins were discovered during a similar experiment to this one.
The sample is injected into a second cell in G2 of interphase.
As a result, the second cell enters mitosis.
A sample of cytoplasm is removed from a cell in mitosis.

9. Protein Regulators- Proteins that respond to events inside the cell
allow the cell cycle to proceed only when certain processes have happened inside the cell.
External Regulators- Proteins that respond to events outside the cell
direct cells to speed up or slow down the cell cycle.

10. III. Uncontrolled Cell Growth
Lung Cancer

11. Cancer- grows out of normal cells in the body
Cancer- grows out of normal cells in the body. Normal cells multiply when the body needs them, and die when the body doesn't need them.
Cancer appears to occur when the growth of cells in the body is out of control and cells divide too quickly. It can also occur when cells forget how to die.
Cancer cells do not respond to the signals that regulate the growth of most cells.

12. Tumors- Masses of cells that results from the uncontrolled division of cancer that can damage the surrounding tissues.
Intramural fibroid tumors on ovaries

13. Cancer cells may break loose from tumors & spread throughout the body, disrupting normal activities & causing serious medical problems or even death.

14. There are many different kinds of cancer
There are many different kinds of cancer. Cancer can develop in almost any organ or tissue, such as the lung, colon, breast, skin, bones, or nerve tissue.
There are many causes of cancer, including:
Benzene and other chemicals
Drinking excess alcohol
Environmental toxins,
Excessive sunlight exposure
Genetic problems
Obesity
Radiation
Viruses

15. Henrietta Lacks Video