Enzymes

Introduction to Enzymes

Introduction to Enzymes

Introduction to Enzymes

Enzymes are biological catalysts that make chemical reactions happen faster by offering an alternative pathway with lower activation energy. The enzyme is not changed in the chemical reaction but facilitates the reaction.
Below is what occurs. The enzyme (E) and substrate(S) noncovalently bind and change shape to form an enzyme-substrate complex (E-S). This is the binding step. The enzyme substrate complex then goes through a change to become the enzyme and product (P). This is the catalytic step.

E + S = ES → E + P

PencilWhy do the enzyme and substrate form a non-covalent bond rather than a covalent bond?

Types of Enzymes

Enzymes are divided into groups — one method is by the type of reactions that they catalyze.

These groups are:

Oxidoreductases which catalyze oxidation reduction reactions.

Transferases which catalyze the transfer of a functional group from one molecule to another.

Hydrolases which catalyze the addition of water and the breaking of a bond. These are often digestion reaction

Lyases which catalyze the addition of a group to a double bond or the removal of a group to make a double bond.

Isomerases catalyze the rearrangement of a functional group in a molecule or change isomers from one type to another.

Ligases catalyze the condensation (joining) of two molecules or the addition of carbon dioxide. Ligases do two different things to four different bonds (C-C, C-O, C-S, and C-N).

3-dimensional Jmol Display

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