1. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu CANCER how does it happen?

2. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Do Now Read article on pg 203 hand out and answer review questions.

3. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Changes in mitosis Aging Cancer

4. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu AGING Mitosis begins after fertilization and continues until death. All living things age. The rate of mitosis slows down with age. As a result of a slowing mitosis rate in humans these things can happen: hair loss, wrinkled skin, loss of calcium in bones and muscle weakness,

5. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Normal Control of Cell Division Cell division in eukaryotes is controlled by many proteins. Called cyclins Control occurs at four main checkpoints. What are they? P 229 BSCS

6. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Checkpoints in cell cycle Cell Growth - G1 – proteins control whether the cell will divide ***Unreplicated DNA - S – Check DNA before it replicates DNA synthesis - G2 – DNA repair enzymes check the results of DNA replication Mitosis -M – If the cell passes this checkpoint proteins will signal the cell to exit mitosis

7. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Control of cell cycle you tube Control of the Cell Cycle

8. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Cyclins Proteins that regulate the a cell’s progression through the cell cycle

9. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Cyclin Cyclin – a protein that controls the cell cycle CDK – (Cyclin Dependant Kinase) binds to cyclin to form MPF A Kinase is an enzyme that activates proteins MPF – (Maturation Promoting Factor) helps start M phase)

10. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Formation of MPF brings past G2 checkpoint An abnormal cell should not be able to pass checkpoint

11. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu When Control is Lost: Cancer Cancer result if cells do not respond to control mechanisms. And start growing uncontrollably

12. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu CANCER – Cells mutate and grow, passing checkpoints Normally a mutant cell is destroyed or self destructs. Called Apoptosis This does not occur in cancer cell

13. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Cancer cell division Unlike normal cells, cancer cells continue to divide indefinitely, even if they become densely packed. Cancer cells will also continue dividing even if they are no longer attached to other cells.

14. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Metastasis A cancer tumor grows and spreads to other parts of body

15. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Causes of Cancer 1)carcinogen - Any substance that can induce or promote cancer. Tobacco, other chemicals, ultraviolet radiation 2) Mutagens – A substances that cause mutations.

16. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Mutations of certain genes cause cancer proto-oncogenes, which regulate cell growth. Become oncogenes which cause uncontrolled mitosis leading to tumors tumor-suppressor genes, which prevent cell division from occurring too often. When these genes mutate it may lead to cancer. Malignant tumors invade and destroy healthy tissue and can spread to other parts of the body. This process is called metastasis.

17. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Effect of Mutation on Gene Expression

18. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu KINDS OF CANCER Carcinomas- tumors grow in the skin and lining of organs. Ex. Lung and breast cancer Sarcomas- tumors that grow in bone and muscle tissue. Lymphomas- tumors that grow in the lymph and blood. Ex. Leukemia.

19. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Gene Expression When the genes in the DNA control the proteins that are made as organism grows Cancer is when there is a mutation of the genes that are reproduced during cell cycle The cells keep making more copies of the cancer genes, and start building cancer proteins (tumors)

20. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Reflection Read cancer article handout again And read cancer focus on page 228, BSCS Write a reflection about what you have learned about cancer in your notebook