Definition

Noun: 1. A highly reactive atom or molecule: A free radical is an atom or group of atoms that contains at least one unpaired electron in its outer shell. This unpaired electron makes the particle unstable and highly reactive, as it seeks to pair with another electron to achieve stability. 2. A cellular damaging agent: In biological contexts, a free radical is typically a reactive oxygen species that can damage cellular components like DNA, proteins, and cell membranes by "stealing" electrons from nearby molecules, a process called oxidation.

Usage Examples

• Noun:
  • Antioxidants in fruits and vegetables help neutralize harmful free radicals in the body.
  • The chemist studied the behavior of the free radical in the chemical reaction.
  • Exposure to pollution and sunlight can increase the production of free radicals.

Advanced Usage

• "Scavenge free radicals": A common phrase in biochemistry and nutrition referring to the action of antioxidants, which donate electrons to stabilize free radicals without becoming destabilized themselves.
  • Vitamin C is known for its ability to scavenge free radicals.

Variants and Related Words

• Radical (noun, chemistry): Often used interchangeably with "free radical" in scientific contexts, though "radical" can sometimes refer to a stable molecular group.
• Reactive Oxygen Species (ROS) (noun): A broader biological term that includes free radicals like the superoxide anion, as well as other reactive molecules derived from oxygen.
• Antioxidant (noun): A substance that inhibits oxidation and can neutralize free radicals.

Synonyms

• Reactive species
• Oxidizing agent (in the context of causing oxidative damage)

Related Concepts

• Oxidative Stress (noun): A physiological condition that occurs when the production of free radicals exceeds the body's ability to neutralize them with antioxidants, leading to potential cellular damage.
  • Chronic inflammation can lead to oxidative stress.
• Unpaired Electron (noun): The defining feature of a free radical; an electron that occupies an atomic or molecular orbital by itself.

Noun

1. an atom or group of atoms with at least one unpaired electron; in the body it is usually an oxygen molecule that has lost an electron and will stabilize itself by stealing an electron from a nearby molecule
   • in the body free radicals are high-energy particles that ricochet wildly and damage cells