brief calculation of telomere loss 07-20-2014d1317

2014-08-29

brief calculation of telomere loss 07-20-2014d1317

skin cells divide about 65 times a day or once about every 30 min- 1.5 hr
-http://www.ask.com/question/how-often-do-skin-cells-divide which references http://anthro.palomar.edu/biobasis/bio_2.htm


brief calculation of telomere loss. We start with about 15,000 kb, then lose 200 bp with each cell division. The critically short length of telomeres is 77 bp. How many cell divisions until this point?
15,000*bp-200*y=77*bp -> y = 74.6 cell divisions

74.6 cell divisions would be reached by skin cells in 74.6*90*min = 6,714 min or 4 days 15 hours 54 min

Clearly humans don't age that fast (in 4-5 days) so many of the skin cells we have dividing must have derived from some stem cells expressing telomerase.