You are studying regulation of the yeast enzyme glutamine synthetase (GS), which is encoded by the GLN1 gene. You have isolated two mutants, designated  gln2– and gln3–, that give decreased GS activity. Mating of either gln2– or gln3– haploids to wild type produces heterozygous diploids that show normal amounts of GS expression. When you cross either a gln2– or gln3– haploid to a gln1– strain the resulting diploids show normal expression of GS.

The GLN1 gene shows a rather complex regulation in response to different amino acids. When either glutamate (glu) or glutamine (gln) is added to the medium, the amount of GS expression diminished and when both glutamate and glutamine are added to the medium GS expression is shut off completely. The effects of different mutants on the response to glu and gln are shown below.

Which of the models from best fits these experimental results? Complete the model for the regulation of GLN1 that includes the effects of glu and gln.      

#Question id: 893

#Unit 1. Molecules and their Interaction Relevant to Biology

Like E.coli eukaryotic cells also contain chaperonin, which of the following in eukaryotic chapronin is incorrect?

#Question id: 894

#Unit 1. Molecules and their Interaction Relevant to Biology

When stress conditions arise, or when protein synthesis threatens to overwhelm the protein-folding capacity of the ER, unfolded proteins can accumulate. These conditions trigger the unfolded protein response (UPR)

a) unfolded protein response ensures to reduces the rate of protein synthesis by mTOR pathway

b) Amyloid aggregates that form before the UPR can come into play may be removed. Some are degraded by autophagy

c) Amyloid aggregates that can be removed by other mechanism such as lysosomal degradations

d)  UPR also bring the various systems into alignment by increasing the concentration of chaperones in the oxygen deprived conditions

Which of the following statements would be incorrect?

#Question id: 895

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following is van’t Hoff plot equation?

#Question id: 896

#Unit 1. Molecules and their Interaction Relevant to Biology

van’t Hoff plot is drawn between

#Question id: 897

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the plot is correct for van’t Hoff equation?

#Question id: 898

#Unit 1. Molecules and their Interaction Relevant to Biology

Protein folding can be followed in the laboratory by measuring which of the following

A) viscosity.

B) electrophoretic mobility and gel filtration.

C) UV absorption and light rotation.