Fad

A fad or trend is any form of behavior that develops among a large population and is collectively followed enthusiastically for a period of time, generally as a result of the behavior being perceived as popular by one's peers or being deemed "cool" by social or other media. A fad is said to "catch on" when the number of people adopting it begins to increase rapidly. They normally fade quickly once the perception of novelty is gone.

Overview

The specific nature of the behavior associated with a fad can be of any type including language usage, apparel, financial investment and even food. Apart from general novelty, fads may be driven by mass media programming, emotional excitement, peer pressure, or the desire to "be hip". Fads may also be set by popular celebrities.

Though the term trend may be used interchangeably with fad, a fad is generally considered a quick and short behavior whereas a trend is considered to be a behavior that evolves into a relatively permanent change.

In economics, the term is used in a similar way. Fads are mean-reverting deviations from intrinsic value caused by social or psychological forces like those that cause fashions in political beliefs or consumption goods.

Flavin adenine dinucleotide

In biochemistry, flavin adenine dinucleotide (FAD) is a redox cofactor, more specifically a prosthetic group, involved in several important reactions in metabolism. FAD can exist in three (or four: flavin-N(5)-oxide) different redox states, which are the quinone, semiquinone, and hydroquinone. FAD is converted between these states by accepting or donating electrons.

FAD, in its fully oxidized form, or quinone form, accepts two electrons and two protons to become FADH₂ (hydroquinone form). The semiquinone (FADH^·) can be formed by either reduction of FAD or oxidation of FADH₂ by accepting or donating one electron and one proton, respectively. See the mechanism section below for details.

A flavoprotein is a protein that contains a flavin moiety, this may be in the form of FAD or flavin mononucleotide (FMN). There are many flavoproteins besides components of the succinate dehydrogenase complex, including α-ketoglutarate dehydrogenase and a component of the pyruvate dehydrogenase complex, some examples are shown in section 6.

FAD (disambiguation)

In other uses, FAD or fad may refer to: