Important Questions of Molecules and their Interaction relevant to Biology Life Sciences | Zigya

Previous Year Papers

Download Solved Question Papers Free for Offline Practice and view Solutions Online.

Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.
Advertisement

 Multiple Choice QuestionsMultiple Choice Questions

Advertisement
201.

Which of the following is NOT true for cholesterol metabolism?

  • HMG-CoA reductase is the key regulator of cholesterol biosynthesis.

  • Biosynthesis takes place in the cytoplasm.

  • Reduction reactions use NADH as cofactor.

  • Cholesterol is transported by LDL in plasma.


202.

Penicillin acts as a suicide substrate. Which one of the following steps of catalysis does a suicide inhibitor affect?

  • k1

  • k2

  • k3

  • k4


203.

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?

  • Ammonia > Oxygen > Sulphur dioxide > Carbon dioxde

  • Oxygen > Caron dioxide > Sulphur dioxide > Ammonia

  • Sulphur dioxide > Oxygen > Ammonia > Carbon dioxide

  • Ammonia > Sulphur dioxide > Carbon dioxide > Oxygen


204.

Choose the most appropriate pH at which the net charge is zero for the molecule from the data shown below:

  • 2.02

  • 2.91

  • 5.98

  • 6.87


Advertisement
205.

Choose the correct statement about peptides in the Ramachandran plot.

  • Peptides that are unstructured will have all the backbone dihedral angles in the disallowed regions.

  • It is not possible to conclude whether a peptide adopts an entirely helix or entirely beta-sheet conformation.

  • The occurrence of beta-turn conformation in a peptide can be deduced.

  • The sequence of a peptide can be deduced.


206.

Equilibrium constant (K'eq) of a reaction is a ratio of product to substrate concentrations. The relation between (K'eq) and free energy change in a reaction (G') is as follows

G' = -RT ln K'eq

Reaction A and Reaction B have K'eq values of 10 and 100, respectively. Which of the following statements is correct with respect to G'?

  • G' of A = G' of B

  • G' of A > G' of B

  • G' of B > G' of A

  • G' of A  G' of B


207.

Which one of the following describes the primary function of flippases?

  • Help in increasing lipid-protein interaction in the outer leaflet of the bilayer.

  • Move certain phospholipids from one leaflet of the membrane to another.

  • Localize more negatively charged membrane proteins in the lipid bilayer.

  • Cause uncoupling of v-SNARES and t-SNARES after fusion of incoming vesicle with the target membrane.


208.

The gel to liquid crystalline phase transition temperature in phosphatidyl choline (PC) lipids composed of dioleocyl (DO), dipalmitoyl (DP), disteroyl (DS) and palmitoyl oleoyl (PO) fatty acids in increasing order will be

  • DOPC > DPPC > POPC > DSPC

  • DSPC > DPPC > POPC > DOPC

  • DPPC > DSPC > DOPC > POPC

  • POPC > DPPC > DOPC > DSPC


Advertisement
209.

The herbicide, dichlorophenyldimethylurea, is an inhibitor of

  • shikimate pathway for biosynthesis of aromatic amino acids

  • electron transport from P680 to P700.

  • branched chain amino acid pathway.

  • electron transport from P700 to ferredoxin.


210.

An optical measurement of a protein is taken both before and after the digestion of the protein by a protease. In which of the following spectroscopic measurements the signal change, i.e. before vs after protease treatment, could be the maximum?

  • Absorbance at 280 nm

  • Circular dichroism

  • Absorbance at340 nm

  • Fluorescence value


Advertisement