Causes of Cell Death VI—VIII

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

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

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

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

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

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