Pathoma: Free Radical Injury

Question 1

Reactive oxygen species are generated during ______.

Answer 1

oxidative phosphorylation

Question 2

When oxygen accepts electrons it becomes ________.

Answer 2

superoxide for one (O2-), hydrogen peroxide for two (H2O2), hydroxyl radical for three (OH-), and water for four

Question 3

The _______ free radical is the most damaging.

Answer 3

hydroxyl

Question 4

_______ converts oxygen to superoxide.

Answer 4

NADPH oxidase

Question 5

Superoxide (O2*) is converted to hydrogen peroxide by _______.

Answer 5

superoxide dismutase

Question 6

What are four pathologic categories of free radical formation?

Answer 6

Inflammation, ionizing radiation, metal cations, and drugs such as acetaminophen

Question 7

In what disease is there an excess of copper?

Answer 7

Wilson’s disease

Question 8

How exactly do free radicals damage cells?

Answer 8

They peroxidize lipids (such as membranes) and directly damage DNA and proteins.

Question 9

What three ways can free radicals be neutralized?

Answer 9

Antioxidants (such as glutathione), enzymes such as catalase, and metal carrier proteins (which bind metal and prevent it from creating more free radicals)

Question 10

What enzyme handles hydroxyl free radicals?

Answer 10

Glutathione peroxidase

Question 11

CCl4, a molecule used in dry cleaning, is damaging because _________.

Answer 11

the liver converts it to CCl3* (a free radical), which prevents protein action in the liver and reduces the liver’s ability to export fat

Question 12

Free radicals can also be generated by _______.

Answer 12

reperfusion injuries (in which blood supply is occluded and then returns suddenly)