Aging and cellular senescence

Question 1

4 characteristics of aging

Answer 1

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

Question 2

what is replicative senescence

Answer 2

limit of replicating capacity and cell stop dividing

Question 3

what is name of limit of divisions

Answer 3

hayflick limit

Question 4

what is werner’s syndome

Answer 4

rare disease where cells don’t replicate as many times

Question 5

problems with link between RS and aging (3

Answer 5

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

Question 6

what are telomeres

Answer 6

short repeat DNA sequqnces at the end of chromosomes

Question 7

purpose of telomeres

Answer 7

1. ensure complete replication of DNA

2. prevent chromosome fusion

Question 8

what happens to telomeres with more reps

Answer 8

progressively shortened and cannot completely replicate 3’ end

Question 9

consequences of shortened telomeres

Answer 9

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

Question 10

2 cells that have no RS

Answer 10

1. stem cells and germ cells

Question 11

how are telomeres maintained in these cells

Answer 11

telomerase enzyme acts to maintain length

Question 12

what happens in cancer

Answer 12

rapid shortening of telomeres, but an activation of telomerase

Question 13

evidence of genetic infulence on longevity (3)_

Answer 13

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

Question 14

what types of genes seem to be involved in lifespan

Answer 14

genes that are involved in stress

Question 15

how much of lifespan is determined by genes

Answer 15

15%

Question 16

what is possible mechanism of genetics on aging

Answer 16

influence through mitochondrial DNA

Question 17

what happens with coloric restriction

Answer 17

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

Question 18

is caloric restriction a true effect

Answer 18

seems to be above weight maintenance

Question 19

what is restriction problem in human

Answer 19

1. trial difficult

2. people ornnery

Question 20

what is mediator of calorie restriction and lifespan

Answer 20

sirtuins

Question 21

how do sirtuins work (2)

Answer 21

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

Question 22

what is resveratrol

Answer 22

plant phonole found in red wine - sirtruin activating