Common Functional Classes of Enzymes

Hydrolase

General term for enzymes that catalyze a hydrolytic cleavage reaction

Nuclease

Breaks down nucleic acids by hydrolyzing bonds between nucleotides

Protease

Breaks down proteins by hydrolyzing peptide bonds between amino acids

Ligase

Joins two molecules together; DNA ligase joins two DNA strands together end-to-end

Isomerase

Catalyzes the rearrangement of bonds within a single molecule

Polymerase

Catalyzes polymerization reactions such as the synthesis of DNA and RNA

Kinase

Catalyzes the addition of phosphate groups to molecules.

Protein kinases are…

an important group of them that attach phosphate groups to proteins.

phosphatase

Catalyzes the hydrolytic removal of a phosphate group from a molecule

Oxido-reductase

General name for enzymes that catalyze reactions in which one molecule is oxidized while the other is reduced. Enzymes of this type are often called oxidases, reductases, or dehydrogenases.

ATPase

Hydrolyzes ATP. Many proteins have an energy-harnessing ATPase activity as part o f their function, including motor proteins ie: myosin and membrane transport proteins ie: sodium pump.

Enzyme names typically end in…

-ase

exceptions: pepsin, trypsin, thrombin, lysozyme, etc. (Were named before ending became common convention)