free radical

noun

, Chemistry, Biochemistry.

1. an atom or molecule that bears an unpaired electron and is extremely reactive, capable of engaging in rapid chain reactions that destabilize other molecules and generate many more free radicals: in the body, deactivated by antioxidants, uric acid, and certain enzyme activities.

free radical

noun

1. an atom or group of atoms containing at least one unpaired electron and existing for a brief period of time before reacting to produce a stable molecule Sometimes shortened toradical Compare group

free radical

1. An atom or group of atoms that has at least one unpaired electron and is therefore unstable and highly reactive. In animal tissues, free radicals can damage cells and are believed to accelerate the progression of cancer, cardiovascular disease, and age-related diseases.

Word History and Origins

Origin of free radical¹

First recorded in 1895–1900

Example Sentences

Seaweed is valued for its antioxidant properties, which helps protect cells against free radical damage.

From Salon

They developed an interacting, triple catalytic cycle in which a photocatalyst -- an iridium-based compound -- is exposed to light, initiating a process that generates a transient free radical, while a second cycle using light regenerates the photocatalyst.

From Science Daily

The free radical generated from photochemistry comes into play here, entering the enzyme active site and engaging the enzymatic intermediate to enable new chemistry.

From Science Daily

Left unchecked, free radical activity damages cells and ultimately may result in skin aging and skin cancer.

From Science Daily

When the scientists created the synthetic melanin engineered nanoparticles, they modified the melanin structure to have higher free radical scavenging capacity.

From Science Daily