Presentation on theme: "Control of the Cell Cycle. Normal Control of the Cell Cycle Enzymes control cell cycle by monitoring progress from phase to phase. Some enzymes are needed."— Presentation transcript:
Normal Control of the Cell Cycle Enzymes control cell cycle by monitoring progress from phase to phase. Some enzymes are needed to begin and keep the cell cycle running. Enzyme production is regulated by genes – Genes are segments of DNA that control the production of a protein.
MUTANT NINJA CELL DIVISION! Sometimes, cells lose control of the cell cycle. This can be due to: – Failure to produce certain enzymes – Overproduction of enzymes – Production of enzymes at the wrong time – Environmental factors Uncontrolled cell division is CANCER!
When does this happen? The period of Interphase before DNA replication is a critical point in the cell cycle. Some scientists think this is when most mistakes in the cell cycle occur because there are several enzymes that need to trigger DNA replication at this point.
Why does CANCER occur? Cancer is due to a change in one or more of the genes that produce enzymes involved in controlling the cell cycle. Cancerous cells form masses of tissue called tumors that deprive normal cells of nutrients. Eventually, cancer cells will invade the rest of the body and affect organ function (metastasis)
How common is CANCER? Cancer is the second leading cause of death in the United States! It can affect any tissue in the body. In the United States, the most common kinds of cancer are: – Lung – Breast – Colon – Prostate
Causes of Cancer: Both Genetic and Environmental Environmental Factors – For immigrants, cancer rates follow the pattern of the country in which people live, not their country of origin. – Cigarette smoke – Air/Water Pollution – Exposure to UV rays – Viral infections All of these damage the genes that control the cell cycle.
Cancer Prevention Diets low in fat and high in fiber Vitamins and minerals, especially carotenoids, A, C, E, and calcium. Daily exercise No tobacco use