Lecture on Cellular Injury and Free Radicals

Flashcards created to review key concepts from the lecture on cellular injury and the role of free radicals.

What is a free radical?

A chemical species with an unpaired electron in the outer orbit that can induce damage within the cell.

How can free radicals be generated physiologically?

Through oxidative phosphorylation, during which oxygen accepts electrons.

What do we call the free radical produced when oxygen accepts one electron?

Superoxide.

What is the most damaging free radical?

Hydroxyl free radical.

What is the role of NADPH oxidase in the formation of free radicals?

It converts oxygen to superoxide during the oxygen-dependent killing mechanism of neutrophils.

What is the Fenton reaction?

A reaction in which free iron generates free radicals, primarily hydroxyl radicals.

How do free radicals damage cells?

By peroxidizing lipids and oxidizing proteins, which can lead to DNA damage and increased cancer risk.

What is the function of transferrin?

To bind iron in the blood to prevent free radical generation.

Name three enzymes that help eliminate free radicals.

Superoxide dismutase, catalase, and glutathione peroxidase.

What is a classic example of free radical injury related to hepatic damage?

Carbon tetrachloride exposure leading to fatty change in the liver.

What is reperfusion injury?

Cell damage that occurs when blood and oxygen are restored to ischemic tissue, leading to free radical generation.

What are cardiac troponins used to indicate in terms of cellular injury?

They leak into the blood as a sign of irreversible injury to cardiac cells.

What process involves the combination of inflammatory cells and oxygen leading to further tissue damage?

Reperfusion injury.