1. Causes of Cell Death VI—VIII

2. VI. Genetic Derangement
Disorders of the cell that are caused by a flaw in DNA
May be inherited or a mutation
Effects range from unnoticeable to death

3. VII. Nutritional Imbalances
Too much or too little food can affect cells
Ex. Anorexia

4. VIII. Aging Theories on why cells age: 1. Time —cells have a lifespan
2. Wear and tear —cells accumulate errors over time to the point at which they cannot efficiently function

5. Time Theory
During cancer studies, scientists found out that telomeres affect a cells lifespan
Telomeres are the tips of the chromosomes and, sort of, keep the DNA from unraveling
Think plastic tip on shoelaces

6. Telomeres on Chromosomes ©http://images. google. com/imgres

7. Telomeres consist of 15,000 base pairs
With every cell division, approximately 300 of these are lost
How many divisions will occur before there is no more telomere left?
50 divisions
Once gone, the cell enters quiescence