BIOCHEMISTRY - Textbook - Ostapchenko L. I. - 2012

Chapter 7. ENZYMOLOGY

7.3. Cofactors and Coenzymes

Most Enzymes require low-molecular-weight non-protein Organic compounds (Coenzymes) and/or Metal Ions (Cofactors) to exhibit catalytic activity. The term "coenzyme" was introduced in the early 20th century to denote the portion of certain enzymes that easily dissociates from the protein molecule and passes through a semipermeable membrane during dialysis. It was later established that most enzymes consist of a heat-labile protein moiety and a heat-stable non-protein factor, the coenzyme. The protein part is termed the "apoenzyme," which is catalytically inactive in the absence of the coenzyme. The coenzyme and the protein molecule (apoenzyme) together form the catalytically active holoenzyme.



Last update: 06/08/2026

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