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TLS Online TPP Program

#Question id: 20318

Which statement is not correct about bacterial quorum sensing?

#Unit 4. Cell Communication and Cell Signaling
  1. The regulation of gene expression in response to fluctuations in cell-population density.
  2. A type of bacterial interaction is found to be involved in the development of antibiotic resistance by the pathogenic microorganisms.
  3. In quorum sensing (QS), small molecules (QS factors), often called ‘auto-inducers’, serve as signals that are recognized in a population-independent manner.
  4. Allows bacteria to monitor the environment for other bacteria and to alter behaviour on a population-wide scale in response to changes in the number and/or species present in a community 
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TLS Online TPP Program

#Question id: 33228

#Unit 1. Molecules and their Interaction Relevant to Biology

If velocity of the reaction is increased by proton abstraction by a species, mechanism is called as
TLS Online TPP Program

#Question id: 33229

#Unit 1. Molecules and their Interaction Relevant to Biology

The effects of pH on enzymes depends on a combination of factors: 
(a) Most enzymes are active within only a narrow pH range, typically 5 to 9. 
(b) the ionization states of the amino acid residues involved in the catalytic activity of the enzyme
(c) the variation of protein structure (usually significant only at extremes of pH).
Which of the above is correct
TLS Online TPP Program

#Question id: 33230

#Unit 1. Molecules and their Interaction Relevant to Biology

The pH dependence of the rate of the reaction catalyzed by fumarase produces the following curve. Which amino acid/s likely to be present in the active site
TLS Online TPP Program

#Question id: 33231

#Unit 1. Molecules and their Interaction Relevant to Biology

Which character makes concerted acid–base catalysis a common enzymatic mechanism?
TLS Online TPP Program

#Question id: 33232

#Unit 1. Molecules and their Interaction Relevant to Biology

In RNase A 
TLS Online TPP Program

#Question id: 33233

#Unit 1. Molecules and their Interaction Relevant to Biology

The pH dependence of the rate of the RNase A reaction suggests the involvement of 
a. Two ionizable residues with pK values of 5.4 and 6.4
b. Single ionizable residue with pK values 7
c. Cytosine residue in active site