Common Types of Enzymes

Hydrolases

catalyzes a hydrolytic cleavage reaction; subclasses include nucleases & proteases

Nucleases

Breaks down nucleic acids by hydrolyzing bonds b/w nucleotides. Endonucleases cleave nucleic acids within, and exonucleases cleave nucleic acids from the ends of the polynucleotide chains.

Proteases

Breaks down proteins by hydrolyzing bonds b/w aa

Synthases

Synthesizes molecules in anabolic reactions by condensing two smaller molecules together

Ligases

Join together (ligate) two molecules in an energy-dependent process.

Ex: DNA ligase joins two DNA molecules together end-to-end through phosphodiester bonds

Isomerases

Catalyzes the rearrangement of bonds w/in a single molecule

Polymerases

Catalyzes polymerization reactions such as the synthesis of DNA and RNA

Kinases

Catalyzes the addition of a phosphate group to a molecule.

Phosphatases

Catalyzes the hydrolytic removal of a phosphate group from a molecule

Oxido-reductases

(General name) Catalyzes reactions in which one molecule is oxidized while the other is reduced.

Specific enzymes: oxidases, reductases, dehydrogenases

ATPases

Hydrolyzes ATP.

Some proteins that have ATPase activity as part of their function: motor proteins like myosin and membrane transport proteins like the sodium-potassium pump

GTPases

Hydrolyzes GTP. Many GTP-binding proteins are GTPases with central roles in the regulation of cell processes.