Sample qn 5-20

Question :

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5.The intrinsic enzyme activity associated with the alpha subunit of regulatory G-protein is a:

Options:

Kinase that transfers the gamma-phosphate of GTP to serine residues of proteins.

GTPase that hydrolyzes GTP to GDP.

Guanylate cyclase that converts GTP to cGMP.

cGMP dependent kinase 6.Vitamin K is required to carboxylate the following amino acid residue of clotting factors:   Options:   Glutamate. Aspartate. Histamine. Kistamine. 7. Which of the following is not associated with carbohydrate antigen?   Options:    Polyclonal B cell stimulation. Memory response. T-independent immune response. Poor immunogenecity.   8. Cellular energy generation is severely compromised in thiamine deficiency because thiamine pyrophosphate (TPP) is:   Options:   A major co-factor for oxidation-reduction reactions.  An essential co-factor for pyruvate and alphaketoglutarate dehydrogenases. Co-factor for transketolase Necessary for utilizing amino acid for energy via transamination. 9.The mechanism that permits immunoglobulins to be synthesized in either a membrane bound or secreted form is:   Options:   Allelic exclusion. Class-switching. Differential RNA processing. The one turn/two turn joining rule. 10.Folding of newly synthesized proteins is accelerated by all except:   Options:   Protein disulphide isomerase. Zinc finger motifs Prolyl cis-trans isomerase. Chaperons. 11. In the Lac Operon, CAP (catabolite gene activation protein) is responsible for its:   Options:   Positive regulation. Negative regulation. Constitutive expression. Attenuation. 12. Glutathione does all the functions except:   Options:   Convert hemoglobin to methemoglobin. Scavenge peroxides and free radicals. Form sulphur conjugates for detoxication of compounds. Act as a cofactor for some enzymes. 13.Isotypic determinants are:   Options:   Subtle amino acid differences encoded by different alleles of isotype genes. Constant region determinants distinguishing each Ig class and subclass. Generated by conformation of amino acid sequences of the heavy and light chain variable regions. Regions present on antigens and specifically bind to antibody 14. One of the following is not a second messenger:   Options:   Cyclic AMP. Guanylyl cyclase. Diacylglycerol. Inositol triphosphate   15. Pertussin Toxin does not lead to:   Options:   ADP -ribosylation of G alpha-one protein. Inhibition of adenylyl cyclase.  Opening of Ca channels. Decreased affinity of G protein for GTP. 16. The mechanism that permits immunoglobulins to be synthesized in either a membrane bound or secreted form is:   Options:   Co-dominant expression. Class switching. Allelic - exclusion. Differential RNA processing. 17.Ribosomes have which of the following enzymatic activity:   Options:   GTPase tRNA Aminoacyl synthetase Peptidyl Transferase. Peptidase Question : 18.Actin, heat shock protein 70 and hexokinase are homologous because they:   Options:   Belong to the same fold family but have different functions Do not belong to the same superfamily. Evolved from a common gene. Have similar functions but derived from different ancestral genes. 19.Mineralocorticoid receptors are present in all except   Options:   Colon Distal nephron. Hippocampus Liver 20.Prions are infectious proteins that:   Options:   Are virus-coded. Cleave proteins. Catalyze differently folded state of a protein. Protect disulfide bonds from being oxidized.