#Question id: 875
#Part-B Specialized Branches in Biotechnology
Why positive phi angles less common than negative Phi angles in proteins contain L amino acid?
#Question id: 877
#Part-B Specialized Branches in Biotechnology
The sharp transition seen in Figure suggests that
A. Proteins can be denatured by any treatment that disrupts the weak bonds stabilizing tertiary structure, such as heating, or by chemical denaturants such as urea or guanidinium chloride.
B. A comparison of the degree of unfolding as the concentration of denaturant increases reveals a sharp transition from the folded, or native, form to the unfolded, or denatured form, suggesting that only these two conformational states are present to any significant extent.
C. A similar sharp transition is observed if denaturants are removed from unfolded proteins, allowing the proteins to fold.
D. Protein folding and unfolding is an “all or none” process that results from a cooperative transition .
#Question id: 880
#Part-B Specialized Branches in Biotechnology
The classic work of Christian Anfinsen in the 1950s on the enzyme ribonuclease revealed the relation between the amino acid sequence of a protein and its conformation. Ribonuclease is a single polypeptide chain consisting of 124 amino acid residues cross-linked by four disulfide bonds. Anfinsen’s plan was to destroy the three-dimensional structure of the enzyme and to then determine what conditions were required to restore the structure.
The critical observation of Anfinsen that the denatured ribonuclease, freed of urea and b -mercaptoethanol by dialysis;
I. The sulfhydryl groups of the denatured enzyme became reduced by air, and the enzyme spontaneously refolded into a catalytically active form.
II. These experiments showed that the information needed to specify the catalytically active structure of ribonuclease is contained in its amino acid sequence.
III. The 105 wrong pairings have been picturesquely termed “scrambled” ribonuclease.
IV. He found that scrambled ribonuclease spontaneously converted into fully active, native ribonuclease when trace amounts of b -mercaptoethanol were added to an aqueous solution of the protein.
Choose incorrect options;
#Question id: 880
#Part-A Aptitude & General Biotechnology
The classic work of Christian Anfinsen in the 1950s on the enzyme ribonuclease revealed the relation between the amino acid sequence of a protein and its conformation. Ribonuclease is a single polypeptide chain consisting of 124 amino acid residues cross-linked by four disulfide bonds. Anfinsen’s plan was to destroy the three-dimensional structure of the enzyme and to then determine what conditions were required to restore the structure.
The critical observation of Anfinsen that the denatured ribonuclease, freed of urea and b -mercaptoethanol by dialysis;
I. The sulfhydryl groups of the denatured enzyme became reduced by air, and the enzyme spontaneously refolded into a catalytically active form.
II. These experiments showed that the information needed to specify the catalytically active structure of ribonuclease is contained in its amino acid sequence.
III. The 105 wrong pairings have been picturesquely termed “scrambled” ribonuclease.
IV. He found that scrambled ribonuclease spontaneously converted into fully active, native ribonuclease when trace amounts of b -mercaptoethanol were added to an aqueous solution of the protein.
Choose incorrect options;
#Question id: 881
#Part-B Specialized Branches in Biotechnology
______and ________ are the first chaperones a newly made prokaryotic protein encounters. Subsequently, many partially folded proteins are handed off to other chaperones to complete the folding process. E. coli can tolerate the elimination of_______ or________, but not both, thereby indicating that they are functionally redundant.
#Question id: 882
#Part-B Specialized Branches in Biotechnology
Choose correct statements about thermophilic proteins
I. The proteins found in thermophilic species are much more stable than their mesophilic counterparts.
II. All thermostable proteins have such a high incidence of salt bridges
III. the most important of which are an increased size of the protein’s hydrophobic core, an increased size of the interface between its domains and/or subunits, and a more tightly packed core as evidenced by a reduced surface-to-volume ratio.
IV. Several of these thermostable enzymes have a superabundance of salt bridges on their surfaces.