Enzymes quiz Flashcards
Oxidoreductase function
transfer electrons from one molecule to the other
Oxidoreductase naming
[e- donor] : [e- acceptor] [oxidoreductase]
Transferase function
transfer functional groups from one molecule to the other
Transferase naming
[reactant receiving functional group] [functional group] [transferase]
Hydrolase function
bond cleavage with addition of water or bond formation with removal of water
Hydrolase naming
[compound to be cleaved] [hydrolase]
Lyase function
group elimination to form double bond
Lyase naming (no C-C bonds broken)
[compound with single bond] [lyase]
Lyase naming (C-C bond broken)
[compound with C-C bond cleaved] [synthase]
Isomerase function
intramolecular rearrangements
Isomerase naming
[reactant] [isomerase]
Ligase function
bond formation from ATP cleavage or bond cleavage from ATP formation
Ligase naming (1/2)
[reactant] : [reactant] [ligase]
Ligase naming (2/2)
[compound formed] [synthetase]
Proximity & Orientation definition
substrate bound in proper alignment to and next to catalytic amino acids
Proximity & Orientation recognition
substrate binding to active site
Proximity & Orientation purpose
increase reaction rate by limiting diffusion and maximizing alignment of reacting functional groups
Preferential Binding of TS definition
enzymes bind TS with higher affinity than substrates or products
Preferential Binding of TS recognition
additional contacts made to unstable intermediate (TS) relative to substrate or product
Preferential Binding of TS purpose
increase reaction rates by lowering TS energy
Acid/Base Catalysis definition
enzyme donates or accepts proton to another aa or substrate
Acid/Base Catalysis recognition
a protonated aa gets deprotonated, or a deprotonated aa gets protonated
Acid/Base Catalysis purpose
stabilize leaving groups (general acid), increase nucleophilicity (general base), stabilize TS
Covalent Catalysis definition
enzyme forms covalent bond with substrate
Covalent Catalysis recognition
deprotonated aa nucleophilically attacks substrate
Covalent Catalysis purpose
provides new reaction pathway
Electrostatic Catalysis definition
charge on enzyme interacts with a neighboring charge
Electrostatic Catalysis recognition
charge on enzyme interacts with a neighboring charge
Electrostatic Catalysis purpose
substrate specificity and orientation, stabilize charges forming
Metal Ion Catalysis definition
metal ion in active site participates in catalysis
Metal Ion Catalysis recognition
metal ion in active site
Metal Ion Catalysis purpose
charge stabilization, water ionization, electron transfer
