A.
Amide group of asparagine
✓
B.
Hydroxyl group of serine activated to an alkoxide ion
✓
C.
Methyl group of alanine
✓
D.
Guanidinium group of arginine
✓
A.
Act as the primary nucleophile
✓
B.
Form a hydrogen bond with histidine and enhance its basicity
✓
C.
Bind the N terminus of the substrate
✓
D.
Donate a proton directly to the leaving group
✓
A.
Acting as a molecular scaffold
✓
B.
Shuttling protons and electrons such as NAD? or FAD
✓
C.
Forming a thioester bond
✓
D.
Transferring methyl groups
✓
C.
Bimolecular encounter of enzyme and substrate
✓
D.
Conformational change
✓
A.
Initial substrate binding
✓
B.
Diffusion of enzyme and substrate
✓
C.
Chemical conversion of substrate into product
✓
A.
More intermediate steps with lower activation energy barriers
✓
B.
Fewer intermediate steps
✓
C.
A single step without a transition state
✓
D.
Higher activation energy
✓
B.
Allosteric regulation
✓
C.
Coenzyme binding domain
✓
A.
Nucleophilic catalyst
✓
C.
General acid catalyst
✓
D.
Allosteric modulator
✓
A.
Providing a macroenvironment that neutralizes all charges on the substrate
✓
B.
Using covalent catalysis to form a stable enzyme substrate intermediate
✓
C.
Preferentially binding and stabilizing the transition state of the reaction
✓
D.
Lowering the pH of the bulk solution to non specifically hydrolyze the substrate
✓
A.
Providing a microenvironment different from the bulk aqueous solution
✓
B.
Orienting the substrates precisely for a reaction
✓
C.
Increasing the local concentration of substrates
✓
D.
Permanently increasing the average kinetic energy of the substrate population
✓
B.
Binding site for hydrophobic side chains
✓
C.
General base catalyst
✓
D.
Metal chelating ligand
✓
B.
Electrostatic catalysis
✓
A.
Attract substrates from distant cells
✓
B.
Bind substrates close together and in the correct orientation
✓
C.
Generate a new substrate molecule
✓
D.
Increase proximity to regulatory molecules
✓
A.
Forming transient covalent bonds
✓
B.
Using charged side chains to stabilize charge in the transition state
✓
C.
Creating a completely non polar environment
✓
D.
Mechanically unfolding the substrate
✓
A.
Increase the kinetic energy of all molecules in the reaction mixture
✓
B.
Provide a surface with a specific shape and chemical groups for the substrate
✓
C.
Alter the standard free energy change to make the reaction exergonic
✓
D.
Combine permanently with the product to shift the equilibrium forward
✓
A.
Strong, irreversible covalent bonds
✓
B.
Weak, non covalent interactions that allow transient and reversible binding
✓
C.
Permanent dipole moments
✓
D.
Hydrophobic forces excluding all water
✓
