Question

A patient says she has read that free radicals might be partly responsible for the development of her disease process. She wants to know more information and if there is anything that can counteract free radicals. The nurse's explanation will be based on understanding that all of the following statements are true EXCEPT

1) an example of a free radical is cytochrome oxide.
2) free radical molecules initiate harmful reactions such as lipid peroxidation, which damages the lipids of cell membranes.
3) the body's way to counteract free radicals include enzymes such as superoxide dismutase.
4) free radicals are molecules that are in a highly reactive state and can be calmed by taking certain vitamins.

Answer 1

Free radicals are highly reactive molecules that can cause cellular damage, but can be countered by antioxidants. Examples of free radicals include hydroxyl radicals and superoxide. Defense mechanisms in the body, such as detoxification, enzymes like superoxide dismutase, and vitamins like C, E, and β-carotene act as antioxidants.

Step-by-step explanation:

Free radicals are highly reactive molecules that can cause cellular damage and are thought to play a role in various diseases. They contain unpaired electrons and can oxidize other molecules in the cell. While cytochrome oxide is not an example of a free radical, examples such as reactive oxygen species (ROS) include the hydroxyl radical (OH), hydrogen peroxide (H2O2), and superoxide (O2).

Free radicals initiate harmful reactions, such as lipid peroxidation, which damages cell membrane lipids. To counteract free radicals, the body uses defense mechanisms like detoxification and cellular antioxidants. Enzymes like superoxide dismutase and vitamins like C, E, and provitamin β-carotene act as antioxidants. Antioxidants neutralize free radicals by being oxidized themselves, stopping the destructive chain reactions initiated by the free radicals.

While vitamin C is a radical scavenger, vitamin E is an antioxidant. The new radicals generated in scavenging reactions are less reactive and easily excreted. However, accumulated reactive oxygen species (ROS) can overwhelm the body's antioxidant defenses.