1. Control of the Cell Cycle Cancer

2. Objectives Why do some types of cells divide rapidly, while others divide slowly? What tells a cell when it is time to leave one part of the cell cycle and begin the next?

3. Proteins and enzymes control cell cycle What controls the cell cycle: Cyclins (protein) and a set of enzymes that attach to the cyclin and become activated The interaction of these molecules based on the conditions in and out of the cell, control the cell cycle

4. Enzyme Production Directed by genes on the chromosomes What is a gene? Segment of DNA that controls the production of protein Many studies point to the portion of interphase just before DNA replication as the key control period in the cell cycle

5. What causes cancer? Occasionally, cells lose control of the cell cycle What causes them to lose control? Failure of cell to produce certain enzymes Overproduction of enzymes Production of enzymes at the wrong time Environmental factors Cancer – malignant growth resulting from uncontrolled cell division

7. Lung Cancer

8. Cancer Is caused by a mistake in the cell cycle Currently, scientists consider cancer to be a result of changes in one or more of the genes that produce substances involved in controlling the cell cycle. Changes are expressed as cancer when something prompts the damaged genes into action

10. Cancer Cancerous cells form masses of tissue called tumors that deprive normal cells of nutrients. In later stages, cancer cells enter the circulatory system and spread throughout the body (metastasis) Form new tumors that disrupt the function of organs, organ systems and ultimately the organism

12. Cancer 2 nd leading cause of death in the US, exceeded only by heart disease Can affect any tissue in the body Most prevalent cancers in the US: lung, colon, breast and prostate

13. Causes of Cancer Involve both genetic and environmental factors Different cancers are more prevalent in different parts of the world Environmental Cigarette smoke, air and water pollution, exposure to UV rays from the sun Genetic Viral infections that damage the genes Carrier of gene that makes you at higher risk (breast cancer: BRCA1, BRCA2 gene)

14. Cancer Prevention Scientists have established a clear link between a healthy lifestyle and the incidence of cancer Diets low in fat and high in fiber Diets high in fat are linked to increased risk of breast, colon and prostate cancers People who limit fat intake reduce their risk and also maintain a healthy body weight High fiber diets linked to a reduced risk of colon cancer  Fruits, vegetables and grains = high fiber content Vitamins and minerals may also help to prevent cancer Keys in this category: caratenoids, Vit A, C & E, calcium  Caratenoids and Vit A  yellow & orange vegetables, and green leafy vegetables  Vitamin C  citrus fruits  Vitamin E  SUN  Calcium  dairy products Making healthy choices, exercising and avoiding carcinogens help to reduce your risk for cancer