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

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

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)

Why do cells stop dividing?

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

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

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

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

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

Model 3: Telomere Disintegration

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

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

How Long? Some scientists suggest that the human body has the potential to live for years with telomerase therapy

Is Telomerase the fountain of youth?

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