Question

3. What statement about the peptide bond is TRUE?

            a. Hydrolysis of the peptide bond is both thermodynamically and kinetically favorable.

       b. Kinetic stability of the peptide bond is overcome by the increased nucleophilicity of the catalytic residue of the protease.

           c. Formation of the acyl-enzyme intermediate distorts the resonance of the peptide bond.

       d.The catalytic strategy of proteases needs to overcome the thermodynamic stability of the peptide bond by making the carbonyl carbon more reactive.

       e.The catalytic strategy of proteases needs to overcome both the thermodynamic and the kinetic stability of the peptide bond.

Match (6 points)

a. ATCase       _____                          1. Protein phosphorylation catalyst

b. T state         _____                          2. Required to modify glutamate

c. R state         _____                          3. Activates a particular kinase

d. Phosphorylation ______                 4. Proenzyme

e. Kinase         _______                      5. Activates trypsin

f. Phosphatase _______                      6. Common covalent modification

g. cAMP          _______                      7. Inhibited by CTP

h. Zymogen     _______                      8. Less-active state of an allosteric protein

i. Enteropeptidase _______                9. Initiates extrinsic pathway

j. Vitamin K    _______                      10. Forms fibrin

k. Thrombin    _______                      11. More-active state of an allosteric protein

l. Tissue factor _______                     12. Removes phosphates

Answer 1

3.

b. Kinetic stability of the peptide bond is overcome by the increased nucleophilicity of the catalytic residue of the protease.

Match

A. 6
B. 8
C. 11
D. 7
E. 1
F. 12
G. 3
H. 4
I. 5
J. 2
K. 10
L. 9