#Question id: 721
#Unit 1. Molecules and their Interaction Relevant to Biology
Addition of urea leads to a two-state transition between α-helix and random coil conformation. It has been observed that [θ]222 of the polypeptide is -11000 deg cm2 dmol-1 in the presence of 6M urea. Initially it was observed that tile values of mean residue ellipticity at 220 nm ([θ]220) are -36000, and +4000 deg cm2 dmol-1 for α-helix, and random coil conformations of this polypeptide. The percentage of the polypeptide in α-helix conformation is:
#Question id: 5166
#General Aptitude
Which of the following is the largest ?
#Question id: 32396
#Unit 1. Molecules and their Interaction Relevant to Biology
#Question id: 10820
#Unit 10. Ecological Principles
Of the following types of interactions, which one is least likely to limit population size?
#Question id: 4267
#Unit 3. Fundamental Processes
The 3D structure of the complete Escherichia coli ribosome with bound mRNA and tRNAs revealed that the very amino terminus of one protein (L27) does reach into the active site. This finding suggested a role for this protein in catalysis. To test this possibility, the nine amino acids at the L27 amino terminus that were in close proximity to the active site were eliminated by mutation. The following possible outcomes were found to be correct as
A. The resulting cells produced ribosomes with reduced but detectable peptidyl transferase activity
B. Region of the L27 protein contributes to peptidyl transferase activity
C. The mutant ribosomes, didn’t synthesised wildtype levels of cells
D. Vast majority of this increase in peptide bond formation is retained, even without the presence of L27 in the active site
E. The most likely role for L27 is to correctly position one or more of the RNA components of the active site