BIO 155 - Topic 4

rate of metabolism theories

Every organism has an energy bank account, when used up, senescence and death result

error catastrophe theory

Genes are amplified into RNA and finally protein products. When genes become damaged, the result is amplified throughout the body with faulty RNA and proteins, leading to senescence

hayflick phenomena

Normal cells in the body appear to have preprogrammed number of divisions; cancer cells seem to escape this

cross-linkage theories

as we age, key structural proteins tend to cross link with other proteins. these proteins include a major structural protein called collagen. some proteins in the body are also enzymes, so it can impact biochemical pathways.

Gene mutation and faulty DNA repair theories

as we age, the number of mutations accumulating in the body increases. eventually, some of these mutations can have dire consequences (cancer). also appears as though some genes get turned off or put in heterochromatic form

death gene theory

as we get older, deleterious or harmful genes are activated, causing senescence

mitochondrial theories

damage to mitochondria and free radicals they produce account for senescence; mitochondria are main sources fro free radials and these products are released by damaged mitochondria and other damaged cells

beta amyloid

found in heart, brain, and blood vessels, major finding in Alzheimers diseased brains and amyloidosis

free radical theory

free radicals gradually accumulate as we age causing cross lining damage to collagen and enzymes; antioxidants protect against free radical damage

somatic mutation theory

harmful factors that affect genes accumulate as we age, including UV radiation, toxic chemicals, free radicals

faulty DNA repair theory

normal body mechanisms that repair DNA do not function as well, when we age. as a result, mutations in the genome accumulate as we age causing misreadings, functional issues, cancers, and symptoms of aging

cellular garbage theory

potentially harmful substances accumulate in the body and cells as we age. these substances interfere with normal cell and body functions; includes: lipofucsin and beta amyloid

important antioxidants

- superoxide dismutase, catalase, peroxidase

Program or genetic theory of aging

- we are preprogrammed by our genes to age - best illustrated by family history, death gene theory, hayflick phenomena, telomere theory

lipofucsin

age pigment waste produce found in the brain and heart tissue

network theories

aging is a combination of many of the theories mentioned

immune system theories

aging is caused by a decline in the immune system; immune system fails to recognize cancer cells and it can attack the body causing autoimmune disorders

hormone and neuroendocrine theories

aging is caused by imbalances of the endocrine and nervous systems control of that system

Wear and tear theories

aging is the accumulation of injuries and damage to body parts caused by living and disease processes ex: osteoarthritis and skin aging

theory of relativity

suggest time is light as it moves through space

telomere theory

the ends of chromosomes, called telomeres, shorten each time they divide; highly disposable segments

dietary or caloric restriction

thought to interact with SIRT genes which promote DNA repair, rebuild telomeres, enhance immune system, inhibit metabolic pathways (slow metabolism - less free radicals)

potent antioxidants

vitamin C and E