Aging and cellular senescence Flashcards Preview

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Flashcards in Aging and cellular senescence Deck (22):
1

4 characteristics of aging

1. external changes
2. physiological and structural changes
3. decreased ability to maintain homeo when stressed
4. increase age related diseases and death

2

what is replicative senescence

limit of replicating capacity and cell stop dividing

3

what is name of limit of divisions

hayflick limit

4

what is werner's syndome

rare disease where cells don't replicate as many times

5

problems with link between RS and aging (3

1. may not work in vivo
2. previous studies now being refuted
3. werner's not exactly aging

6

what are telomeres

short repeat DNA sequqnces at the end of chromosomes

7

purpose of telomeres

1. ensure complete replication of DNA
2. prevent chromosome fusion

8

what happens to telomeres with more reps

progressively shortened and cannot completely replicate 3' end

9

consequences of shortened telomeres

1. incomplete replication of genes next to telomere
2. lack of capping may result in abnormal chromosome fusions
3. activation of DNA damage response and cell cycle arrest

10

2 cells that have no RS

1. stem cells and germ cells

11

how are telomeres maintained in these cells

telomerase enzyme acts to maintain length

12

what happens in cancer

rapid shortening of telomeres, but an activation of telomerase

13

evidence of genetic infulence on longevity (3)_

1. mono twins more similar life spans than dizygotics
2. differences in genetically inbred mice
3. specific genes have been ided that affect lifespan

14

what types of genes seem to be involved in lifespan

genes that are involved in stress

15

how much of lifespan is determined by genes

15%

16

what is possible mechanism of genetics on aging

influence through mitochondrial DNA

17

what happens with coloric restriction

60% of normal calories leads to 40% longer life in mice

18

is caloric restriction a true effect

seems to be above weight maintenance

19

what is restriction problem in human

1. trial difficult
2. people ornnery

20

what is mediator of calorie restriction and lifespan

sirtuins

21

how do sirtuins work (2)

1. induce expression of genes whose products increase stress resitiance
2. increase insulin sensitivity and glucose metabolism

22

what is resveratrol

plant phonole found in red wine - sirtruin activating

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