The Ageing Process

Question 1

What is a telomere?

What does it consist of and what does this form?

What happens to this over time?

What is this process known as?

Answer 1

The end of a chromosome arm

Consists of multiple repeats of TTAGG which form a DNA loop

This progressively shortens after each cell replication, until it is too short to sustain cell replication

The Hayflick limit

Question 2

What is telomerase?

Which type of cells is this active in and why?

Answer 2

A protein which can re-extend shortened telomeres

Stem cells and immune cells - need to divide many times

Question 3

What are some factors which can cause damage to macromolecules, leading to mutations, lipid peroxidation and protein misfolding?

Answer 3

Ionising radiation

Reactive oxygen species (diet, radiation, inflammation)

Extrinsic toxins

Question 4

Frailty is defined as a loss of homeostatsis and resilience. This leads to increased vulnerability to what?

Being frail increases the risk of what things?

Answer 4

Decompensation after a stressor event

Falls, delirium, disability and death

Question 5

What are some ways to increase survival in old age?

Answer 5

Not smoking

Being social

Physical activity