By-products Of Metabolism

Question 0

What does superoxide dismutase do? (SOD)

Answer 0

Catalyses the reaction of superoxide radicals together to form hydrogen peroxide

Question 1

How are ROS produced?

Answer 1

When an electron in the ETC prematurely reduces an oxygen to produce O2-

Question 2

Which enzyme breaks down hydrogen peroxide and what does it break it down into?

Answer 2

Catalase

Oxygen and water

Question 3

How does glutathione reduce ROS

Answer 3

The thiol (-SH) group in cysteine can donate its H and therefore act as a reducing agent.

Question 4

What is the oxidised form of glutathione?

Answer 4

Glutathione disulphide (GSSG)

Question 5

How is glutathione disulphide converted back to glutathione?

Answer 5

NADPH reduces it.

Question 6

Which two vitamins are antioxidants?

Answer 6

C and E

Question 7

Which drugs in particular are strong oxidising agents?

Answer 7

Anti-malarials

Question 8

What is oxidative stress?

Answer 8

When antioxidant levels are low

Question 9

What can oxidative stress lead to?

Answer 9

Atherosclerosis
Parkinson’s
Alzheimer’s

Question 10

How are ROS involved in immunity?

Answer 10

Neutrophils and monocytes can undergo oxidative bursts, releasing a large quantity of ROS.
This kills any surrounding bacteria or fungal cells.

Question 11

Which enzyme produces the oxidative burst?

Answer 11

NADPH oxidase