Hi everyone!

This week in class we learned about the nine theories of aging. The first theory is called Aging by Program. This theory states that aging begins at birth and that there is a timekeeper. Cells only divide a certain number of times and then they die. The second theory is the Gene Theory and it states that aging is programmed due to bad genes. The third theory is Gene Mutation Theory and it states that accumulation of cells that contain mutations cause the cells to not function properly and eventually die. The fourth theory is the Cross-Linkage Theory and it states that with age, proteins cross-link and are structurally altered. The fifth theory is the Free Radical Theory and it states that if the amount of free radicals in a cell exceed a threshold, the cells become damaged. The sixth theory is the Cellular Garbage Theory which states that accumulations of nonactive and reactive substances interfere with normal functioning of the cell. The seventh theory is the Accumulation of Errors Theory which states that there is an accumulation of random errors in translation of proteins with age. The eighth theory of aging is the Wear and Tear theory which states that cells have a certain amount of metabolic energy and the rate at which the energy is used determines the length of life. The final theory is the Autoimmune theory which states that new antigens cause autoimmune reactions.

I was curious to learn more about the Free Radical Theory because I did not really understand it at first. I found an article that really goes into detail about this theory and allowed me to understand it better. Free radicals have an extra electron which causes the cells to have an extra negative charge (Anti-Aging Today). They bind to other molecules to try and steal electrons. When doing this it causes the other molecule to also become a free radical, thus destroying cells. Free radicals attack cell membranes and create metabolic waste products (Anti-Aging Today).

Link to article: http://www.anti-aging-today.org/aging/theory/free-radical.htm