Multiple Choice QuestionsDenaturation of a highly helical protein having disulfide bridges and two phenylalanine can be monitored as a function of temperature by which one of the following techniques?
Recording circular dichroism spectra at various temperatures.
Monitoring the absorbance at 214 nm at various temperatures.
Estimating the -SH content during heat denaturation.
Monitoring the ratio of absorbance at 214 nm and at 250 nm at various temperatures
In order to separate red and white blood cells, which of the following methods can be used?
Ion-exchange chromatography and FACS.
Hydrophobic chromatography and density gradient centrifugation
Density gradient centrifugation and FACS
Hydrophobic chromatography and FACS
In order to check whether a protein has been phosphorylated during treatment with a drug, you would perform
Southern hybridization
Western blot analysis
ChIP assay
RFLP
A researcher was working with three proteins, A, B, and C which may have potential roles in gene expression. In order to validate the hypothesis, EMSA (electrophoretic mobility shift assay) was performed. The purified proteins were allowed to bind with a labelled DNA and the results obtained after autoradiography are shown below:
The following interpretations were made
(i) Protein A possesses the DNA binding motif.
(ii) Protein B possesses the DNA binding motif.
(iii) Protein B binds to DNA protein A complex.
(iv) Protein C binds to DNA only when protein A is bound.
Choose the correct combination of interpretations.
(i) and (iv)
(i) and (iii)
(ii) and (iii)
(iii) and (iv)
In an experiment designed to clone a PCR-amplified fragment in a cloning vector digested with XhoI (C/TCGAG) and SmaI (CCC/GGG), which one of the following combinations of restriction enzymes can be used in the PCR primer to generate compatible ends for cloning?
('/' indicates the site of cleavage within the recognition sequence)
XbaI (T/CTAGA) and SpeI (A/CTAGT)
EcoRI (G/AATTC) and SmaI (CCC/GGG)
SaII (G/TCGAC) and EcoRV (GAT/ATC)
HindIII (A/AGCTT) and PvuII (CAG/CTG)
Given below are a set of statistical methods/ parameters (Column A) and their potential applications/ utility in biological research (column B), in a random manner.
| Column A | Column B |
| A. Variance | (i) Measures strength of association between two variables. |
| B. Correlation coefficient | (ii) Prediction of value of a dependent variable based on known value of an associated variable. |
| C. Regression analysis | (iii) Calculation of deviation between observed and expected values. |
| D. Chi-square analyses | (iv) Calculate the spread of a distribution. |
Which of the following options is a correct match of entries in Column A and B?
A - (ii); B - (iv); C - (i); D - (iii)
A- (iii); B - (ii); C - (iv); D - (i)
A - (iv); B - (i); C - (ii); D - (iii)
A - (i); B - (iii); C - (ii); D - (iv)
The Nuclear Magnetic Resonance (1D and 2D) spectrum of a 30-residue peptide were recorded at 25°C. The following observations were made.
A. The NH and CαH resonances were well resolved.
B. The NOESY spectra showed extensive N1-Ni+1 connectivities.
C. The NH resonances showed slow exchange with deuterium.
The spectra indicates that the peptide adopts
Helical conformations
Anti-parallel β-strand conformations
Polyproline conformation
β-turn conformation with four amino acids participating in the turn. The rest of the amino acids are unstructured.
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