Oxidative stress

Question 1

What is the definition of Oxidative stress

Answer 1

Where generation of free radicals and ROS is in excess of available antioxidant defenses

Question 2

What is a free radical

Answer 2

molecules with one or more unpaired electrons making them highly unstable and reactive

Question 3

What are ROS and are they bad?

Answer 3

ROS and tools used by cells like using them to microbes, the problem comes when their levels are to high

Question 4

how do Neutrophils and macrophages use ROS’s to kill cells

Answer 4

During phagocytosis there is a large uptake in oxygen, NADPH-oxidase reduces that oxygen to superoxide (oxidative burst) this is done in the phagosome of the bacteria to kill it.

Question 5

ROS DNA damage

Answer 5

ROS damages DNA, DNA cannot be replaced, and all damage must be repaired otherwise mutations will be passed down, but mutations are passed down and ROS are believed to be why we age

Question 6

How does ROS damage proteins?

Answer 6

Cysteine oxidation - sulphur switch