Study Set Content:
complex biological molecules, primarily or entirely protein, which behave as biological catalysts.
ENZYMES
Enzymes are normally very specific in their action, often targeting only one specific reacting species, known as the
substrate
Reactions occur when substrate binds to the (blank)of the enzyme
active site
It performs redox reaction by utilizing electron acceptor such as NAD+ in dehydrogenases H2O2 in peroxidases and oxygen in oxidases
Oxidoreductase
It catalyses by transferring groups like amino, phosphoryl, carboxyl, carbonyl etc. between different substrates. Examples - kinases, transaminases, phosphorylases
Transferases
It performs reactions by adding water which breaks the bonds like phosphodiester bond is broken down by phosphodiesterases, amide bond is broken down by peptidases
Hydrolases
It catalyses by rearranging the compounds forming isomers. Examples -epimerases , mutases, racemases
Isomerases
Groups like CO2 NH2 are either added or removed from the substrate. Examples - aldolases, synthases, decarboxylases
Lyases
Form new bonds by utilizing ATP, Examples - carboxylases and synthases
Ligases
Some enzymes consist entirely of
proteins
Some enzymes consist entirely of proteins, whereas others have non-protein portions known as
cofactors
cofactors
branch into
Inorganic ions
organic
Inorganic ions
zinc
copper
organic
coenzymes
coenzyme/metal ion + enzyme protein
Prosthetic group:
A complete, catalytically active enzyme together with its bound coenzyme and/or metal ions
Holoenzyme
The protein part of such an enzyme is called the
apoenzyme or apoprotein
Cytochrome oxidase
Cu2+
Pyruvate kinase
K+
Cytochrome oxidase, catalase, peroxidase
Fe2+ or Fe3+
