Enzymatic Conversions

Enzymatic Conversions

An enzyme acts on a specific starting molecule, called its substrate, and converts it into a different molecule, called the product. This substrate-to-product change is what is meant by an enzymatic conversion: S -> P, with the enzyme (E) speeding up the change without itself being used up.

Two features make enzymatic conversions special compared to ordinary chemical reactions. First, enzymes are highly specific - a given enzyme generally acts only on one substrate or a small group of closely related substrates, unlike a general chemical catalyst that may work on many different reactions. Second, enzymes are extremely efficient - a tiny amount of enzyme can convert a very large amount of substrate in a short time, and because the enzyme is released unchanged at the end of the reaction, the same enzyme molecule can be used over and over again. These two properties - specificity and r …