Bio 3050 Week 11 - Aging and Longevity
mutations in proto-oncogenes can cause the following...
-cell loses the ability to kill itself -cell develops the ability to hide -cell sends out for resources -cell multiplies quickly
organisms that "live fast" have....
-juveniles that mature quickly -a shorter lifespan -a large number of offspring -minimal parent care -high mortality
organisms that "live slow" have....
-juveniles that mature slowly -a long lifespan -few number of offspring -low mortality -high parental care
what are some tradeoffs of aging and longevity?
-long-lived = small clutch size and slow growth rate -short-lived = large clutch size and fast growth rate
naked mole rats have no changes in bone health until....
24 years old
naked mole rats live....
29 years
archaea and bacteria _____ age
DO
antioxidants
Organic molecules that help protect the body from harmful chemicals called free radicals by offering an extra electron to them
true or false - human and mice cells can go dormant and stop aging
TRUE
mass-adjusted LD50 _______ and showed ______ in a study
accounts for body size; body size isn't everything - some organisms are just more resistant to stressors than others despite body size
the evolution explanation for Peto's paradox is....
as organisms evolved and grew more cells, they had a higher chance of cancer, meaning they had to invest in better cancer defenses or they would die out
reactive oxygens (ROS) damage DNA by....
breaking DNA strands and causing mutations leading to cancer
naked mole rats are resistant to _______ and aging of....
cancer; the cardiovascular system
reactive oxygens (ROS) damage proteins by....
causing aggregation, fragmentation, and enzyme inhibition
reactive oxygens (ROS) damage membranes by.....
causing lipid peroxidation and damage to membranes/lipoproteins
plant meristems/apical meristems
centers of mitotic cell division composed of a group of undifferentiated self-renewing stem cells from which most plant structures arise
body weight is.....
correlated with lifespan
evidence for the free radical theory of human aging includes....
damage to DNA, lipids, and protein, increases in abnormal mitochondria with age, acceleration of age with ionizing radiation, and superoxide dismutase in trisomy 21
what are some other proposed solutions to Peto's paradox?
different metabolic rates or different cellular architecture of small and large organisms
autophagy
eating ones self
free radicals are constantly trying to steal ______ from ________
electrons; healthy atoms
telomeres
end caps that protect the DNA-containing chromosome
what are the two main explanations for Peto's paradox?
evolution and hypertumors
faster metabolic rate =
faster mutation rate, shorter longevity
____________ CAN be related to longevity, but not always
fecundity
oxidative damage has to do with...
free radicals
the free radical theory of human aging
free radicals cause damage to cells throughout the body, which accelerates aging
the one-half rule of mammae to offspring
generally two nipples for every one offspring
bacteria and archaea can only live for hours or days, but if they _________, they can survive for years
go into dormancy within halite/saline solutions
free radicals
have an extra electron - go around the body damaging cells
some animals actively resist free radical damage by preferably choosing foods....
high in antioxidants
bacteria and archaea can live _____ or ______
hours, days
probability of survival plays a role in....
how long an organism will live (small organisms = less defense/lower in food chain, large organisms = more defense/higher in food chain)
__________ becomes the limiting factor for how large a tumor can grow
how many nutrients it can steal from the body for form
a study on naked mole rats, humans, and birds revealed....
humans have the highest life span because they have the lowest peroxidation of cell membranes
Peto's Paradox
if an organism has more cells, its chances of getting cancer should be higher, but large animals seem to be immune to cancer (have much, much less cancer than they should)
higher flavonoid content in food was shown to be correlated with a(n) _________ lifespan in animals
increased
the formation of free radicals occurs from...
ionizing radiation, smoking, UV light, air pollution, inflammation of white blood cells, mitochondrion metabolism
meristematic cells are responsible for....
keeping a plant growing
most cancer cells are....
killed by the immune system very quickly after being produced
bats live a relatively _______ time compared to their body size because....
long; they have increased autophagy
the larger the body size, the __________ the organism
longer-lived (but there's variation in this)
longer-lived species have ________ perioxidation of cell membranes
lower
cancer occurs by...
many individual mistakes and mutations in proto-oncogenes within the same cell
plants have their own "fountain of youth" called a......
meristem
longevity is linked to _____________ rates in rockfish
mitochondrial mutation
________ are the "holy grail" in aging research
naked mole rats
mammae
nipples
what are the two largest mechanisms of aging?
oxidative damage and telomere shortening
damage to membranes, proteins, and DNA from reactive oxygens (ROS) collectively leads to....
oxidative stress, disease, and aging
body size is _________ correlated with longevity
positively
telomere length in early life can....
predict lifespan
tumor supressor genes
prevent mutations in proto-oncogenes from happening or order the cell to kill itself if it's beyond repair
in a study on zebra finches, individuals with shorter telomeres lived __________, while those with longer telomeres lived __________
shorter; longer
slower metabolic rate =
slower mutation rate, longer longevity
carcinogens that are known to cause DNA damage were tested in species and revealed that......
some animals are more resistant to stressors than others
relative telomere length
telomere length relative to the length of the chromosome
as cells divide over time......
telomeres take on a lot of damage and shorten, and eventually cell division stops
lower mutation rates =
tend to live longer
higher mutation rates =
tend to live shorter
LD50
the amount of a chemical that kills 50% of the animals in a test population
a cell can turn into a cancer cell if....
the cell's "kill switch" fails
senescence
the condition or process of deterioration with age - the loss of a cell's power of division and growth
free radicals are a byproduct of _________, which is why they can cause damage to _________ so easily
the energy transfer chain; mitochondria (close to mitochondrion)
the length of time a cluster of cells senescence is directly related to.....
the length of time an organism lives (ex: human clusters last longer than mice clusters)
hypertumors
the tumors of tumors
a study on zebra finches revealed....
there's a positive relationship between relative telomere length and lifespan
how do hyper tumors starve & kill original tumors?
they cut off the blood supply to the tumors and steal if for themselves (can occur over and over)
studies on older mice revealed that....
they react totally differently to drugs than younger mice
true or false - some organisms can be exposed to hundreds of carcinogens but literally cannot get cancer
true
larger animals have more....
tumor supressor genes (they require more mutations than smaller animal cells to develop a tumor)
requiring a higher dose of LD50 to die means....
you're more resistant to the carcinogen