An example of coordinate control is the down-regulation of ribosomal RNA synthesis in response to amino acid starvation, which will cause synthesis of ribosomal proteins to be limited.  What is the correct order of the following events that participate in the signaling process?

1. Binding of stringent factor to the ribosome.

2. Formation of the unusual nucleotide ppGpp.

3. Formation of the unusual nucleotide pppGpp.

4. Uncharged tRNA binds in the ribosomal A-site.

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