bio aging final exam Stochastic Theories.txt

  1. Theoretical Gerontological approach
    Darwinian terms: disposable soma theory
  2. Empirical Aging studies
    Stochastic and Systemic
  3. Arking's Theories of aging
    • 1. stochastic
    • 2. systemic
    • 3. intracellular
    • 4. intercellular
  4. Stochastic mechanism
    • ie: wear-and-tear theory
    • STRENGTH: CAN account for differences WITHIN SAME species
    • WEAKNESS: explaining wide range of mortality among DIFFERENT species (ie two types of mice)
  5. Intracellular Theory
    • Major aging done WITHIN the cell
    • DO NOT account for extracellular processes, wuch as glucose derived collagen
  6. Intercellular Theory
    • Originate OUTSIDE of the cell
    • CANNOT explain SINGLE cell organisms
  7. Which theories are STOCHASTIC, INTRACELLULAR theories
    • Altered Protein
    • Somatic mutation
    • DNA damage and Repair
    • Error catastrophe
    • Dysdifferentiation
    • Oxidative damage
    • But, Posttranslational Protein Modification Theory is STOCHASTIC, INTercellular
  8. Altered Protein Theory
    • Proteins undergo CONFORMATIONAL changes to ALTER function
    • First proposed by ROTHSTEIN
  9. Somatic mutation Theory
    • Altered DNA mutations that CAN be inherited
    • Accumulate overtime in somatic cells, leading to EVENTUAL DEATH
    • Leo Szilard first proposed this
  10. DNA damage and Repair theory
    • Altered DNA mutations that CANNOT be inherited
    • Cells DO NOT recognize these mutations as DNA damage
    • ie: p53 tumor suppressor gene
    • Sonneborn, Bernstein and Ames showed DNA damage in different organisms
    • evidence against this is theoretical and argues that these theories only look at lifespan, NOT mortality rates
  11. Error Catastrophe Theory
    • Altered Amino acid sequences in proteins May cause POSITIVE feedback loop leading to DEATH of cell
    • Orgel first proposed this
  12. Dysdifferentiation Theory
    • Inappropriate protein synthesis in aging differentiated cells
    • Richard Cutler first proposed
  13. Oxidative Damage Theory
    • STRONGEST stochastic theory
    • Denham Harman first proposed: free radical theory
    • Vit E and C important Antioxidants as well as MELATONIN
  14. Free radical theory biomarker studies
    • Oxidative damage and anti-oxidant gene activity Increase in Dros: in short lived strains there is HIGH oxidative damage, and LOW anti-oxidant activity
    • Lippofuscin accumulation is REDUCED in animals given Vit. E supplements
  15. Vitamin E
    Found in inner leaflet of innermitochondrial membrane
  16. Vitamin C
    Found in Highest concentration in cell cytosol
  17. Waste Accumulation Theory
    • Failure of cells to REMOVE waste products (such as LIPOFUSCIN) resulting in BUILDUP of toxins
  18. Wear-And-Tear Theory
    • Traditional explanation of aging (STOCHASTIC)
    • Favored by Aristotle, Maimonides, Bacon and Weismann
    • Molecularly this is correct, but mostly from intrinsic factors, not envir.
  19. Posttranslational Protein Modification Theory
    • Structural changes to EXTRACELLULAR proteins lead to age related pathologies
    • Bjorksten first suggested the CROSSLINKAGE of extracellular molecules
  20. Steps for glycation of collage
    • from Posttranslational protein mod. theory
    • 1. glucose attaches to lysine
    • 2. Schiff base converted to Amadori product (IRREVERSIBLE)
    • 3. Amadori product attaches to the 2nd lysine
Card Set
bio aging final exam Stochastic Theories.txt
bio aging final exam STOCHASTIC Theories