Name: Introduction to Enzymes
Uploaded: 2023-04-30T10:09:27
Description: Learn by watching this video about Introduction to Enzymes at JoVE.com

Enzymes are biological catalysts that accelerate reaction rates without being consumed.&#160; They are typically proteins located in the cytoplasm, inside organelles, and in cell or organelle membranes.
Enzymes may function intracellularly or can be secreted extracellularly. Most enzymes require a specific temperature and pH to operate at peak efficiency.
Substrates are the reactants that specifically bind to active sites, small regions on the enzyme where the reaction occurs. The remaining parts of the enzyme provide structure to the enzyme or interact with other molecules to promote or inhibit the reaction.
Enzymes change their shape to bind their substrates and catalyze the conversion of substrates into products.&#160; After the reaction, the enzyme releases the product and returns to its original conformation, which allows the enzyme to catalyze additional rounds of the reaction.
Some enzymes only function when associated with cofactors, which assist an enzyme-catalyzed reaction. Non-protein molecules such as vitamins, metal ions, or ATP act as cofactors for various enzymes.

<ol>
	<li>Heckmann, C. M., &#38; Paradisi, F. (2020). Looking back: A short history of the discovery of enzymes and how they became powerful chemical tools. ChemCatChem, 12(24), 6082-6102.</li>
	<li>Nelson D. L &#38; Cox M.M. Principles of Biochemistry 5th ed.W. H. Freeman and Co.&#160; pp. 182-184</li>
</ol>

introduction to enzymes

The use of enzymes by humans dates to 7000 BCE. Humans first used enzymes to ferment sugars and produce alcohol without knowing that this was an enzyme-catalyzed reaction. Wilhelm Kuhne coined the term &#39;enzyme&#39; in 1877 from the Greek words &#8216;en&#8217; meaning &#8216;in&#8217; or &#8216;within&#8217; and &#8216;zyme&#8217; meaning &#8216;yeast.&#8217;
Most enzymes are proteins that speed up biochemical reactions without being consumed. Enzymes contain one or more active sites that bind the substrates and convert them into products. Many enzymes also have allosteric sites, additional sites where molecules other than substrates bind to activate or inhibit the enzyme.
Some enzymes require the presence of cofactors&#8211; metal ions or organic molecules for catalysis. Cofactors bind to the active site of an enzyme and assist in the conversion of substrates into products. An enzyme without a cofactor is an apoenzyme and becomes a holoenzyme once it binds a cofactor. A cofactor that is an organic molecule is called a coenzyme. Most coenzymes are vitamin-derived.
Inhibitors are molecules that stop an enzyme-catalyzed reaction. Competitive inhibitors are similar to substrate molecules and compete with them to bind to the active sites. In contrast, non-competitive inhibitors bind to allosteric sites and change the enzyme conformation to reduce substrate binding.

Learn by watching this video about Introduction to Enzymes at JoVE.com