Biology of Aging Flashcards
What is Aging?
Time-related deterioration of the physiological functions necessary for survival and reproduction
What are the 3 major theories of aging?
- Aging Theories
- Programmed (genes or hormones)
- Damaged or Error (wear and tear & oxidative stress)
Who discovered age-1 (hx546) mutation? What does this cause to lifespan?
Tom Johnson
- 65% increase in mean lifespan
- 110% increase in maximum lifespan
- Remains youthful for longer
Who discovered mutations in daf-2? What does this cause?
Cynthia Kenyon
- greatly increase lifespan
Genes regulating dauer formation and life span in C. elegans showed that it does what to lifespan?
Increased lifespan
In Drosophila melanogaster, Mutations in INR (fly daf-2) caused what?
mean female lifespan increased by up to 85%
In Drosophila melanogaster, mutation of chico (insulin receptor substrate) caused what?
Increases lifespan by up to 48%
What implications were shown by the Drosophila melanogaster mutations?
Wide evolutionary conservation of the role of insulin/IGF-signaling in the modulation of aging: a universal mechanism of aging
Loeb and Northrop showed that increasing temperatures cause what to Drosophila melanogaster lifespan?
Reduces it!
The faster your heart beats, the shorter or longer you live?
shorter
T/F: The life energy potential is constant
TRUEEEE!!!!
Rapid metabolism = ____ life spans
Shortest
Slower metabolic rates = tend to have ____ life spans
LONGER
Explain briefly the Free Radical Theory of Aging and their connection with caloric restriction
- Aging is a result of oxidative damage caused by free radicals generated by the metabolic system
- Free radicals are unstable organic molecules
- Damage: lipids, protein, carbohydrates, nucleic acids, various other cell components
- caloric restriction extends life expectancy by reducing oxygen consumption
Explain the Crosslink Theory
- Connective tissue loses elasticity with age (wrinkles, cataracts)
- Loss of elasticity results from the accumulation of cross-linking compounds that cause the collagen to become stiff
- Some of this cross-linking may be caused by free radicals
Explain the Autoimmune Theory
- Immune system begins to decline after adolescence
- vulnerability to disease and a sluggish response to some tumor cells
- system so weakened that it can no
longer distinguish between the body’s own and foreign tissues, i.e. the body may begin to attack itself
What are the primary hallmarks of aging (CAUSES of damage)
- Genomic instability
- Telomere attrition
- Epigenetic alterations
- Loss of proteostasis
What are the antagonistic hallmarks of aging (RESPONSES to damage)
- Deregulated nutrient-sensing
- Mitochondrial dysfunction
- Cellular senescence
What are the Integrative hallmarks (CULRPTIS of the phenotype)
- Stem cell exhaustion
- Altered intercellular communication
What does Glucagon-Like Peptide 1 analogs (OZEMPIC) do?
Reduce insulin sensitivity and increase glucose uptake by cells
