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A protein has 30% alanine. If all the alanines are replaced by glycines, (1) helical content will increase. (2) ß-sheet content will increase. (3) there will be no change in […]

Which is correct for α-helix of a protein (1) It has H-bonding in two or more parallel running chains (2) There is intra-chain H-bonding in single helix (3) No H- […]

The following statements describe the propensity and role of amino acids in the secondary structure of proteins A. Alanine has a high frequency of occurrence in α- helices B. Proline […]

How long should it take the polypeptide backbone of a 6-residue, 10-residue, 15-residue and 20- residue folding nucleus to explore all its possible conformations? Assume that the polypeptide backbone randomly […]

Consider a 51-residue long protein containing only 100 bonds about which rotation can occur. Assume that 3 orientations per bond are possible. Based on these assumptions, how many conformations will […]

26. The length of an α-helical section of a polypeptide chain of 20 residues spanning hydrophobic region of membrane would be (1) 30 A (2) 54 A (3) 5.4 A […]

Indicate which one of the following statements about nucleic acids and protein structures is correct. (1) Hydrogen bonding between the bases in the major and minor grooves of DNA is […]

The following statements were made to describe a typical collagen structure. A. Collagen has a triple-helical domain structure which consists of three distinct α-chains. B. The collagen triple helix is […]

23. Following are statements on ß-turns: A. All the 20 coded amino acids have equal propensity to form ß -turns. B. Pro cannot occur in ß-turns. C. Pro-Gly sequence strongly […]

In a 30-residue peptide, the dihedral angles φ/Ψ have been determined by one or more methods. When their values are examined in the Ramachandran plot, it is (1) not possible […]