Enzymes have a protein backbone but there are also carbohydrate groups which are covalently bonded as well as metal ions which add to their stability (Chaplin, 2004)
Holoenzymes are special. 😉
They consist of apoenzymes which are inactive in their original conformations (proenzymes) and they are the polypeptide/protein part of the holoenzyme. For the formation of the apoenzymes’s final (tertiary) structure, extra amino acids on the proenzyme are removed.
Cofactors are another constituent of holoenzymes. They are usually derived from vitamins, i.e. non-protein substances which may be organic, and called a co-enzyme. Co-enzymes activate the protein by either altering its conformation or by participating in the chemical reaction (Ophardt, 2003).
(whew! mouthful there)
Together, apoenzymes and cofactors form biologically active enzymes containing active sites, which allow them to catalyze chemical reactions by acting upon a specific substrate.
Organic and Inorganic Catalysts face off…
Our buddies the enzymes have some… *ahem* interesting names… 😐 ?.
Ophardt, C. E. 2003. Enzymes. [online] Available at: http://www.elmhurst.edu/~chm/vchembook/570enzymes.html [Accessed: 6 Mar 2014]
Chaplin, M. 2004. Enzyme nomenclature. [online] Available at: http://www1.lsbu.ac.uk/water/enztech/nomenc.html [Accessed: 4 Mar 2014].
Tutorvista. 2014. Classification of Enzymes. [image online] Available at: http://www.tutorvista.com/content/biology/biology-iii/cellular-macromolecules/enzymes-classification.php [Accessed: 5 Mar 2014].
Contributors: India, Roi (Editor)