Milady Esthetics State Board Practice Test

What defines free radicals in a biological context?

1. Molecules that have gained an electron

2. Molecules that have lost an electron

3. Molecules that have stable bonds

4. Molecules that assist in cell regeneration

The correct answer is: Molecules that have lost an electron

Free radicals are defined as molecules that have lost an electron, making them highly reactive and unstable. In a biological context, this instability is significant because free radicals attempt to regain their balance by stealing electrons from nearby molecules. This electron theft can lead to damage in cells, proteins, and DNA, contributing to various health issues and aging processes. The presence of free radicals is often associated with oxidative stress, which is a disturbance in the balance between the production of free radicals and the body's ability to eliminate them. Thus, the characterization of free radicals as molecules that have lost an electron is crucial in understanding their role in biological systems and their impact on health and wellness. The other answers refer to concepts that are unrelated or incomplete in describing free radicals. For example, molecules that have gained an electron would be considered negatively charged ions rather than free radicals. Molecules with stable bonds do not fit the definition since free radicals are defined by their instability. Likewise, molecules that assist in cell regeneration do not necessarily pertain to the concept of free radicals, which are often associated with cellular damage rather than regeneration.