Enzymes

phosphorylase

catalyzes phosphate addition from inorganic phosphate

kinase

catalyzes phosphate addition from ATP or other high-energy phosphate

phosphatase

catalyzes phosphate removal from a substrate

oxidoreductase

catalyzes redox reactions (electron transfer)

types of oxidoreductases

• dehydrogenases - remove H atoms from substrates

• oxidases - transfer electrons from substrates to oxygen (forms water or hydrogen peroxide)

• reductases - catalyze reduction of substrates via electron addition

transferase

catalyzes transfer of functional groups between molecules

types of transferases

• kinases - transfer phosphate groups from (i.e.) ATP to substrates

• aminotransferases - transfer amino groups between amino acids and keto acids

hydrolase

catalyzes hydrolysis of chemical bonds by adding water

types of hydrolases

• proteases - break down proteins into peptides/AAs

• lipases - break down fats into glycerol/FAs

• nucleases - break down nucleic acids into nucleotides

lyase

catalyzes cleavage of chemical bonds without hydrolysis or oxidation (often resulting in double bond or new ring)

types of lyases

• decarboxylases - remove carboxyl from organic acids

• aldolases - split/form C-C bonds

isomerase

catalyzes rearrangement of atoms within a molecule

types of isomerase

• epimerases - convert stereoisomers into one another

• mutases - shift functional groups between positions within a molecule

ligase

catalyzes joining of two large molecules via new chemical bond (often coupled with hydrolysis of high-energy molecule)

types of ligases

• DNA ligase - joins DNA strands during replication/repair

• synthetases - catalyze formation of complex molecules

DNA helicase

unwinds double-stranded DNA by breaking H-bonds between base pairs

topoisomerase

prevents DNA from become tangled by relaxing supercoiling in DNA strands

DNA primase

synthesizes RNA primers as starting points for DNA polymerase

DNA polymerase

builds new DNA strands by adding nucleotides

DNA ligase

joins DNA fragments by forming phosphodiester bonds (5’ carbon of one sugar to 3’ carbon of another)