KEY CONCEPT Cell cycle regulation is necessary for healthy growth.

1. KEY CONCEPTCell cycle regulation is necessary for healthy growth.

2. Objectives for section 5-3 • Describe the internal and external factors that regulate cell division • Relate cancer to the cell cycle.

3. Internal and external factors regulate cell division. • External factors include physical and chemical signals and trigger internal factors, which affect the cell cycle. • Growth factors are proteins that stimulate cell division. -Most mammal cells form a single layer in a culture dish and stop dividing once they touch other cells.

4. Two of the most important INTERNAL factors are kinases and cyclins. -Cyclin, a protein, binds to cyclin-dependent kinases (CDK) to start various activities in cell cycle • Like key in ignition of car • Different combos signal other activities such as DNA replication and protein synthesis

5. Quality Control Checkpoints -Cell cycle has built-in checkpoints that monitor cycle and can stop it if something goes wrong • G1 checkpoint: decision of whether cell will divide • G2 checkpoint: DNA replication is checked • Mitosis checkpoint: triggers exit from mitosis

6. Spindle checkpoints also have been identified in mitosis

7. Apoptosis is programmed cell death • Cells actually shrink and shrivel in a controlled process

8. webbed fingers • Apoptosis is a normal feature of healthy organisms • caused by a cell’s production of self-destructive enzymes • occurs indevelopmentof infants • Falling leaves in Autumn

9. Cell division is uncontrolled in cancer. -Cancer is uncontrolled growth and division of cells -Cancer cells can kill an organism by crowding out normal cells, resulting in loss of tissue function

10. Cancer: Unregulated Cell DivisionUploaded on Sep 30, 2011 YouTube

11. normal cell cancer cell bloodstream Cancer cells form disorganized clumps called tumors. • Benign tumors remain clustered and can be removed. • Malignant tumors metastasize, or break away, and can form more tumors.

12. Cancer cells do not carry out necessary functions. • Cancer cells come from normal cells with damage to genes involved in cell-cycle regulation. • Can be due to mutations (multiple)

13. Various environmental factors can also affect occurrence of cancer cells -Carcinogens are cancer causing substances and agents Skin Cancers

14. Multiple changes in DNA required to change abnormal cell into cancer cell Largest tumor ever - 303lbs Breast cancer cell

15. 16 lb facial tumor Oral cancer • Cancer is “simply” uncontrolled cell growth!

16. As of 2016 (ten years later), MarlieCasseus, now 23, has had ten additional surgeries.

17. Standard cancer treatments typically kill both cancerous and healthy cells. • Radiation, chemotherapy, HeLa cells

18. Dear 16-year-old Me, 5:03 Uploaded on May 2, 2011 - FOR TOOLS & INFORMATION:http://dcmf.ca/tools This film was made possible thanks to the generosity of real Canadians and Americans whose lives have been touched by melanoma. These are not actors. We cannot thank this group enough for sharing their stories with us

19. Quick Quiz Time • Each question will be worth 2 points • You may NOT talk and/or communicate with a classmate • Scores will be collected and recorded at the end of the chapter

20. 7. What is the term for the programmed death of cells? a. kinase b. cyclin c. carcinogen d. apoptosis

21. 8. Which phrase best describes cancer? a. absence of cyclins b. multiple gene mutations c. uncontrolled cell growth d. presence of genetic defects

22. 9. Two internal factors that are important in advancing the cell cycle are a. kinases and cyclins. b. hormones and enzymes. c. phosphates and enzymes. d. proteins and platelets.

23. Trade your paper with a non-lab partner

24. 7. What is the term for the programmed death of cells? a. kinase b. cyclin c. carcinogen d. apoptosis

25. 8. Which phrase best describes cancer? a. absence of cyclins b. multiple gene mutations c. uncontrolled cell growth d. presence of genetic defects

26. 9. Two internal factors that are important in advancing the cell cycle are a. kinases and cyclins. b. hormones and enzymes. c. phosphates and enzymes. d. proteins and platelets.

27. End of Show