Advanced Biochemistry MCQ-23 (PG Level)

The φ and Ψ values of a β-strand composed of all D-amino acids will mainly occupy which quadrant in the Ramachandran plot? (CSIR_2017_II)

Match the coenzymes in column I serving as transient carriers of specific atoms or functional groups in column II

Select correct combinations from the options given below: (CSIR_2017_II)

Out of the statements mentioned below

(A). L-threonine and L-allo-threonine interact identically with plane polarized light.
(B). van der Waals’ interactions are always attractive.
(C). Poly (pro) II-helix is not stabilized by intermolecular hydrogen bonds.
(D).The folding of a protein is associated with an overall positive change in free energy and negative change in entropy.
(E). Lysine acetylation on histone is associated with loosening of the histone complex from DNA.

Which of the following combinations is CORRECT? (CSIR_2017_II)

The following statements are made:

(A). α and β anomers of glucose are inter-convertible and the ratio of their abundance is 1:2, respectively.
(B). Single chain lipids (≥C14) form micelles and double chain lipids form bilayers in water.
(C). Proline is energetically favoured at the Ctermini of an α-helix than at the N-termini.
(D). Major groove of DNA readily accommodates several common structural motifs in protein than the minor groove.
(E). Replacement of a canonical Watson-Crick pairing by Wobble base pairs does not change the surface properties in t-RNA.

Which one of the following combinations is INCORRECT? (CSIR_2017_II)

125^I labeled diaminofluorene DAF) is a well-known photoactivable hydrophobic probe for plasma membrane integral protein. To determine the approximate length and number of hydrophobic domain in any integral membrane protein, a controlled experiment (following standard protocol) is carried out. In order to ascertain the aforesaid aspects indicate the correct combination of experimental protocols from the following choices: (CSIR_2015_I)

The ionic strength of a 0.2 M Na2HPO4 solution will be: (CSIR_2015_II)

A cell line deficient in salvage pathway for nucleotide biosynthesis was fed with medium containing 15N labelled amino acids. Purines were then extracted. Treatment with which one of the following amino acids is likely to produce 15N labelled purines? (CSIR_2015_II)

The solubility of gases in water depends on their interaction with water molecules. Four gases i.e. carbon dioxide, oxygen, sulphur dioxide and ammonia are dissolved in water. In terms of their solubility which of the following statements is correct? (CSIR_2016_I)

Which one of the following statements about receptor – enzyme is FALSE? (CSIR_2016_I)

From the following statements

(A). Enzymes enhance reaction rates by a factor of 2 to 10.
(B). The activation energy for a reaction is lowered by enzymes.
(C). The interactions between enzymes and substrates are hydrogen bonding, hydrophobic and ionic.
(D). Substrate concentration does not affect the rate of enzyme catalyzed reactions.

Pick the combination with all INCORRECT statements. (CSIR_2017_II)