Questions with complete solution
You are studying a protein found in stomach acid (pH 2). The protein has
enzymatic functions that are reliant on a charged Histidine residue in the
protein. Why might this protein not be functional at pH 7.4? - correct answer
✔The Histidine carries a net positive charge at pH 2 but no net charge at
Ph7.4
Hemoglobin is a tetrameric protein that binds to four Oxygen molecules via a
porphorin ring present in each hemoglobin monomer. Hemoglobin binds to
oxygen in a cooperative manner. If Hemoglobin were a monomeric protein i.e.
only one subunit not four, do you think it would still act in a cooperative
manner? - correct answer ✔No because cooperativity is dependent on the
conformation of each monomeric unit affecting the next subunit in the tetramer
Glucose is a 6 carbon sugar. How many stereocenters does LINEAR glucose
have? - correct answer ✔4
Carbohydrates contain two important functional groups that can tautomerize
when catalyzed to do so by enzymes. What are the two functional groups? -
correct answer ✔Aldehydes and Ketones
A small peptide has the following sequence:
Asparagine-Arginine-Aspartate-Glutamate-Glutamine-Glycine-Threonine-
Tyrosine-Tryptophan
Which of the following is the correct sequence using the one-letter
abbreviations for amino acids? - correct answer ✔N-R-D-E-Q-G-T-Y-W
, You have discovered a new amino acid. It is an alpha-amino acid and has a
side chain containing a terminal carboxylic acid group with pKa =6. The net
charge of this amino acid at physiological pH will be: - correct answer ✔-1
A beta-carbon is present in every proteinogenic amino acid except:
A. P
B. A
C. I
D. G - correct answer ✔G
You have discovered a new amino acid. It is an alpha-amino acid and has a
side chain containing a terminal carboxylic acid group with pKa =6. The pI of
this amino acid is approximately: - correct answer ✔4
From the following Ramachandran plots, which of the following amino acids
do you think would be most "flexible": - correct answer ✔
Which of the following is not a property of peptide binds - correct answer
✔They form between the alpha carbon and amino group of amino acids
The local arrangment of amino acids in space" is a broad description of what
level of protein structure? - correct answer ✔Secondary
What type of bonding is crucial for stabilizing protein alpha helicies - correct
answer ✔H bonding between amino acid backbone atoms
You are given a sample to analyze by SDS-PAGE. The sample contains a
single type of protein. It is in a solution containing saline, SDS and 2-
mercaptoethanol. The sample does not contain an enzyme. You run the