1. Controlling the Cell Cycle

2. Controlling the Cell Cycle
The controls on cell growth and division can be turned on and off.
For example, when an injury such as a broken bone occurs, cells are stimulated to divide rapidly and start the healing process. The rate of cell division slows when the healing process nears completion.

3. Controlling the Cell Cycle
Recall that proteins are made by ribosomes.

4. Controlling the Cell Cycle
Recall that proteins are made by ribosomes.
Certain class of proteins called cyclins help control different phases of the cell cycle.
Ex. S-cyclin—helps stimulate DNA replication in S phase (interphase)

5. M-cyclin—triggers mitosis
Cyclins are influenced by another protein called growth factors.

6. The Discovery of Cyclins
Cyclins are a family of proteins that regulate the timing of the cell cycle in eukaryotic cells.
This graph shows how cyclin levels change throughout the cell cycle in fertilized clam eggs.

7. Growth factors
supervise and monitor cells progress through the place of the cell cycle.
--may promote or prevent certain cycles

8. Cancer arises from a faulty cell cycle
is a term to describe a disease characterized by uncontrolled cell division and growth
without regulation of the cell cycle, cell will grow without restraint.

9. Tumor —is a clump of cells that is not regulated Benign—harmless tumor
Malignant—grows and invades other cells

10. Tumor
A benign tumor is noncancerous. It does not spread to surrounding healthy tissue.
A malignant tumor is cancerous. It invades and destroys surrounding healthy tissue and can spread to other parts of the body. The spread of cancer cells is called metastasis. Cancer cells absorb nutrients needed by other cells, block nerve connections, and prevent organs from functioning.

11. Picture from study.com:

13. Tumor sizes Vary

14. Examples of Tumor Size…
Caution next slide may be disturbing for some people…

15. Example of Tumor sizes

16. --faulty cell can produce many changes in a cell, making them different from normal cell
--cancer cell more round and mobile than normal

17. Cell cycle
is regulated in several ways and all must be damaged for cancer to occur

18. Carcinogens —cancer causing to cells
Ex. Smoking, UV rays, radiation, lead

19. Carcinogens —cancer causing to cells
Ex. Smoking, UV rays, radiation, lead

20. A change in your genes, mutation, usually occurs in lungs or skin cells and usually not hereditary

21. If genes in either egg or the sperm are mutated, then there is a greater chance of cancer later in the life of the “new baby”

22. Prevention proper diet exercise
avoid carcinogens (smoke, chemicals, radiation)
UV protection
not smoking

23. Treatment: 1. Radiation Therapy 2. Chemotherapy (“Smart Bomb”)
3. Both (with or without surgery)
4. Surgery