5. EINSTEIN & TIME Traveling at speed of light, time is relative Not only do you not age, but each moment of your existence, past, present and future exists forever

6. If cells can undergo mitotic division, replacing cells with new daughter cells, why are our lifespans finite?

8. HeLa Cells “Immortal Cell Line” Obtained from Henrietta Lacks in 1951 Used to develop polio vaccine and in almost all human studies Cells divide well past Hayflick Limit (50-75 times)

9. Why do cells stop dividing?

10. Three Models For Cellular Senescence Oxidative stress Effects of Prolonged Caloric Intake Telomere disintegration

11. Model 1: Oxidative Stress Free radicals (i.e. peroxides) cause damage to DNA Damaged DNA cannot be replicated or is replicated with mistakes Loss of DNA code = loss of cellular function

12. Combating Oxidative Stress Antioxidants surround and/or remove free radicals Examples: Fruit, Red Wine

13. Model 2: Caloric Intake As cells age, unused glucose combines with protein and iron to create a caramel- like substance that inhibits cell function Cells cannot divide

14. Combating Glycosylation Caloric Restriction Studies show that individuals who cut their caloric intake by 1/3 rd may live 33% longer than individuals who do not

15. Model 3: Telomere Disintegration

18. HeLa & Telomerase HeLa cells retain active versions of telomerase longer than other cells

19. Progeria Telomerase may slow the loss of cellular function due to rapid aging caused by the genetic disease progeria

20. How Long? Some scientists suggest that the human body has the potential to live for 200-300 years with telomerase therapy

21. Is Telomerase the fountain of youth?

23. Cancer & Telomerase Telomerase may be the chemical signal that allows cells to avoid G 0 and continue to divide As cells divide more rapidly, they rush through G 1, G 2 and S subphases Cells reproduce quickly but lose function due to loss of proper form