Coenzymes. Coenzymes: A nonprotein component of enzymes is called the cofactor. If the cofactor is organic, then it is called a coenzyme. Coenzymes are relatively small molecules compared to the protein part of the enzyme. Many of the coenzymes are derived from vitamins.
twoâ²-step`. 1. a ballroom dance in duple meter, marked by sliding steps. 2. a piece of music for, or in the rhythm of, this dance.
Two-Step TB Skin Test. The 2-step test is not the usual PPD skin test in which you receive an injection of PPD and the test area is observed one time at a specific time frame. The 2-step PPD test is used to detect individuals with past TB infections who now have diminished skin test reactivity.