Refer to the following experiment, which is designed to test the co evolutionary relationships among an unpalatable butterfly (the  monarch),  a  palatable  butterfly  (the  viceroy),  and  a  butterfly  predator  (the  jay).  Monarch butterflies are reared on three diets: milkweed (their natural food), cabbage, and cabbage treated with an extract from milkweed leaves. Viceroy butterflies, mimics of monarchs, also are reared on three diets: willows (their natural food), cabbage, and cabbage treated with an extract from milkweed leaves. In trial 1 of the first experiment, adult butterflies reared on a particular diet are presented one at a  time  at  1-hour  intervals  to  jays  and  the  jays  are  allowed  to  feed.  Each jay is  fed  until  it refuses to eat the butterfly presented, but no more than 12 butterflies are presented to a jay during a particular test. Five birds are used for each test; therefore, up to 60 butterflies can be consumed for each diet test. The observer records the actual number of butterflies  eaten. In trial 2, the experiment is repeated 2 weeks later. In the second experiment, the butterflies are reared on the same diets as in experiment 1. However, when they are offered to jays, some jays receive a monarch  reared  on  milkweed  before  being  offered  the  butterflies  reared  on  the  experimental  diets;  the  other  group  of jays is  first given a viceroy reared on willow before being  offered the butterflies reared on the experimental diets. The initial butterfly offered is included in the total number eaten, but no more than 12 butterflies are presented to each jay.

In the experiment, which data in the table most strongly indicate that viceroys are not obtaining compounds that will make them unpalatable?

#Question id: 881

#Part-B Specialized Branches in Biotechnology

 ______and ________ are the first chaperones a newly made prokaryotic protein encounters. Subsequently, many partially folded proteins are handed off to other chaperones to complete the folding process. E. coli can tolerate the elimination of_______ or________, but not both, thereby indicating that they are functionally redundant.

#Question id: 882

#Part-B Specialized Branches in Biotechnology

Choose correct statements about thermophilic proteins

I. The proteins found in thermophilic species are much more stable than their mesophilic counterparts.

II. All thermostable proteins have such a high incidence of salt bridges

III. the most important of which are an increased size of the protein’s hydrophobic core, an increased size of the interface between its domains and/or subunits, and a more tightly packed core as evidenced by a reduced surface-to-volume ratio.

IV. Several of these thermostable enzymes have a superabundance of salt bridges on their surfaces.

#Question id: 882

#Part-A Aptitude & General Biotechnology

Choose correct statements about thermophilic proteins

I. The proteins found in thermophilic species are much more stable than their mesophilic counterparts.

II. All thermostable proteins have such a high incidence of salt bridges

III. the most important of which are an increased size of the protein’s hydrophobic core, an increased size of the interface between its domains and/or subunits, and a more tightly packed core as evidenced by a reduced surface-to-volume ratio.

IV. Several of these thermostable enzymes have a superabundance of salt bridges on their surfaces.

#Question id: 887

#Part-B Specialized Branches in Biotechnology

Polypeptides fold rapidly by a stepwise process, how does the polypeptide chain arrive at its native conformation?

#Question id: 887

#Part-A Aptitude & General Biotechnology

Polypeptides fold rapidly by a stepwise process, how does the polypeptide chain arrive at its native conformation?

#Question id: 891

#Part-B Specialized Branches in Biotechnology

The folding pathways of some proteins require two enzymes that catalyze isomerization reactions such as,

a) Peptide prolyl isomerase (PPI)  catalyzes the elimination of folding intermediates with inappropriate disulfide cross-links

b) Protein disulfide isomerase (PDI) enzyme that catalyzes the interchange, or shuffling, of disulfide bonds until the bonds of the native conformation are formed

c) Peptide prolyl cis-trans isomerase (PPI) catalyzes the interconversion of the cis and trans isomers of Proline residue peptide bonds

d) Peptide prolyl isomerase (PPI) can be a fast step in the folding of proteins that contain some Pro peptide bonds in the cis conformation

Which of the following combinations is correct about protein folding pathways?