FFLD 10

Question 1

Which of the following catalytic strategies does he serine protease chymotrypsin use/apply? (Chose all correct answers)
A. Acid-base catalysis
B. Covalent catalysis 
C. Redox and radical catalysis 
D. Geometric effects
E. Stabilisation of the transition state
F. Cofactors

Answer 1

A, B, E and F

Question 2

The catalytic triad in serine proteases contain which three amino acids?
A. Serine
B. Aspartate
C. Glycine
D. Phenylalanine
E. Tryptophan
F. Histidine

Answer 2

A, B, and F

Question 3

Select the incorrect statement
A. For acid-base catalysis the ionisable groups involved in proton transfer must be in the correct ionisation state.
B. An electrophile is a molecule that acts as an electron pair acceptor. In chemical reactions it accepts an electro pair so that it can bind (with a covalent bond) to a nucleophile.
C. A nucleophile is a molecule that acts as an electron pair donor. They’re electron rich and donate an electron pair to an electrophile.
D. Histidine is not suitable in acid-base catalysis because it’s pKa value is close to the physiological pH (~ pH 7) and is therefore an unstable electron acceptor or donor.

Answer 3

D

Question 4

The local environment can tune the pKa of amino acid side chains. True or false?

Answer 4

True