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