1. Cell Cycle Regulation

2. Cell Cycle Regulation
Regulating the cell cycle is necessary for healthy growth.

3. Mitotic Regulation
There are both internal and external factors that regulate cell division.
External factors include physical and chemical signals.
Proteins that stimulate cell division are known as growth factors.

4. Mitotic Regulation
Most mammalian cells form a single layer in a culture dish and stop dividing once they touch other cells

5. Mitotic Regulation
Two of the most important internal factors are kinases and cyclins (both proteins).
External factors trigger the internal factors which affect the cell cycle.

6. Regulating the Cell Cycle

7. Contact Inhibition
Type of cell to cell communication that tells the cell to stop dividing when an area is full (Remember the healthy growth in the culture dish?).
If a mistake occurs with the cell’s signals, cancer can result.

8. The Body’s Control Mechanism
Apoptosis: Programmed cell death
It is a normal feature of healthy organisms
Caused by a cell’s production of self – destructive enzymes
Occurs during the development of infants

9. Uncontrolled Mitotic Division
Cancer: the uncontrolled dividing of cells
Reasons cancer can occur:
Failure to produce certain enzymes
Overproduction of enzymes at the wrong time
Mutations that occur from copying DNA incorrectly
Environmental factor that changes your DNA

10. Cancer cells Cancer cells form disorganized clumps called tumors
Benign tumors = not cancerous (will not spread and take over healthy cells)
Malignant tumors = cancerous (can metastasize, or break away to take over healthy cells)

11. Treatments Oncologist = doctor who studies cancer
1. Chemotherapy = chemicals injected into body that kill rapidly dividing cells
Problems: tiredness, vomiting, loss of hair, and kills both healthy and cancerous cells

12. Treatments
2. Radiation = laser aimed at cancer that attacks the cells and other healthy cells in that area
Problems: kills other healthy cells that are in the way. Can only be used for surface cancers.

13. Treatments 3. Biopsy = take out whole tissue that is affected
Problems: could miss some of the cancer cells or could make cancer cells grow back even faster then before
A biopsy is also done to initially determine if the tumor is malignant or benign.