Multiple Choice QuestionsA large protein of a pathogenic bacterium has been enzymatically digested to generate a mixture of peptides ranging in size from 3 to 8 amino acids in length. Peptide mixtures were hen administered in experimental animals to generate peptide-specific antibodies. In order to develop diagnostics for the bacteria, the antisera were used for Western blotting to detect bacterial antigen. Western blotting failed despite the use of a wide range of antisera concentrations. What is the most probable cause of the problem?
The peptide-specific antibody mixture is unstable.
Peptide-specific antibodies were not generated as an adjuvant was not administered.
Peptide-specific antibodies were not generated as they were not coupled to a protein carrier.
Peptide-specific antibodies could not recognize the bacterial antigen.
Upon absorption of a photon, a chlorophyll molecule gets converted to its excited state when the energy of the photon is
More than that of the ground state of the pigment molecule
Equal that of the pigment molecule’s excited state
More than that of the ground state but less than of the excited state of the pigment molecule.
Equal to the energy gap between ground state energy and the excited state energy.
The intestinal absorption of glucose is impaired by the use of ouabain, an inhibitor of Na+/ K+ ATPase. Indicates the correct explanation.
The inhibitor has blocked the transport of Na+ from the intestinal lumen to epithelial cells.
The inhibitor has blocked the transport of Na+ from epithelial cells to the intestinal lumen.
The inhibitor has blocked Na+ transport from epithelial cells to the intestinal space.
The inhibitor has blocked Na transport from the intestinal space to epithelial cells.
A person has been suffering from night blindness. On consultation, the doctor advised the person to ear carrots and/ or codfish oil. After some time having seen no improvement, the doctor gave the person vitamin A injection. Still no marked improvement was seen. The doctor several suggestions indicating a lack of the following enzymes for the failure of treatment:
(A) Retinol dehydrogenase
(B) retinal reductase
(C) Retinal isomerase
(D) Retinal synthase
Which one of the following is correct?
(A) only
(B) only
(B) and (C)
(C) and (D)
Which one of the following non-covalent interactions between two non-bonded atoms A and B is most sensitive to the distance between them?
A and B are permanent dipoles and are involved in hydrogen bonding
A and B are fully ionized and are involved in salt bridge formation
A and B are uncharged and repel each other.
A and B are uncharged and attract each other
Which statement best describes the pKa of amino groups in proteins?
pKa of the α-amino group is higher than the pKa of ε- amino group.
pKa of the α-amino group is lower than the pKa of ε- amino group.
pKa of the α-amino group is the same as the pKa of ε- amino group.
pKa of the α-amino group is higher than the pKa of the guanidine side chain of arginine.
A protein has 30% alanine. If all the alanines are replaced by glycines.
helical content will increase
β-sheet content will increase
there will be no change in conformation
the alanine-substituted protein will be less structured than the parent protein
The gel to liquid crystalline transition temperature (Tm) of phospholipids is dependent on the fatty acid composition. Considering this, Tm of
all the phospholipids will be identical
DPPC will be lowest and DOPC will be highest.
POPC and DOPC will be identical and lower than DMPC or DPPC
DOPC will be lowest and DPPC will be highest.
The molar absorption coefficient of phenylalanine is 200 M-1cm-1 at257 nm. What concentration (g/L) of this amino acid will give an absorption of 1 in a cell of 0.5 cm path length at 257 nm?
3.30
0.33
1.65
0.17
Which of the following atomic nuclei cannot be probed by nuclear magnetic resonance spectroscopy?
1H
31P
18O
15N
