Ageing 1: Cellular Mechanisms Flashcards
(8 cards)
1
Q
What factors can lead to mutation/degrading of the genome?
A
- Replicative errors
- Oxidation
- Insertion of viral/transposon DNA
2
Q
Across species, how does rate of mutation correlate to lifespan?
A
Slower mutation accumulation, longer life.
3
Q
Describe, mechanistically, how telomere shortening occurs and its implications
A
- Polymerase can’t replicate DNA all the way to the end
- Telomeres are repetitive “caps” on chromosomes, which protect functional DNA from being lost
- However, after enough replications, telomeres reach a crisis point, and cells enter senescence apoptosis
4
Q
If telomere shortening makes cells eventually go into senescence or apoptosis, why don’t stem cells run out?
A
- They have the enzyme telomerase
- It replenishes stem cells, enabling them to keep dividing
5
Q
Which biological marker has been used to develop biologica vs chronological age clocks?
A
- DNA Methylation
6
Q
Recall cellular hallmarks of aging
A
- Loss of preoteostasis (WIT?)
- Epigenetic modifications
- Telomere shortening
- Genome instability
- Loss of autophagy
7
Q
Loss of proteostasis is a hallmark of aging. What does this mean?
A
Production and accumulation of misfolded, mistranslated, or incomplete proteins in the cell.
8
Q
Describe the cellular mechanics of autophagy, and recall two other cellular processes this is similar to
A
- Recycling of unwanted and damaged material in by lysosomes
- Falls within the same system as phago- and endocytosis
