Enzymes Flashcards
Substrates are able to bind the active site through multiple weak interactions
Enzyme-substrate complex
Enumerate the weak interactions
- Electrostatic interaction
- H-bonding
- Hydrophobic interactions
- Van deer Waal’s forces
Substrate binding is highly specific because of?
Precisely defined arrangement of atoms in the active site
How enzymes are able to single out its substrate from a given pool
Enzyme specificity
A model of enzyme-substrate complex with a site that has a fixed, rigid conformation complementing to the substrate.
Only certain substrates fit the active site of the enzyme
Lock-and-key model by Emil Fischer, 1894
A model of enzyme-substrate interaction with a flexible conformation of the active site.
Enzyme and active site adjust shape to accommodate the substrate
Wide range of enzyme specificity
Induced fit model by Daniel Koshland, 1958
Glucokinase
Best explained by the lock-and-key model
Glucose + ATP => glucose-6-phosphate + ADP
Hexokinase
Induced fit model
Hexose + ATP => hexose-6-phosphate + ADP
A type of enzyme specificity which only catalyze 1 substrate
Ex. Urease = urea as substrate
Absolute specificity
A type of enzyme which is distinguished between stereoisomers
Only L-amino acids are recognized
Stereochemical specificity
A type of enzyme which recognizes structurally similar compounds that have the same functional group
Ex. Carboxypeptidase - recognizes c terminal of peptides
Group specificity
A type of enzyme which act on specific type of bond
Ex. Phosphatases -hydrolyzed phosphate esters
Linkage specificity
