On the molar scale which of the following interactions in a non-polar environment provides highest contribution to the bio-molecule?

• van der Waals interaction   

• Hydrogen bonding   

• Salt bridge   

• Hydrophobic interaction    

Michaelis and Menten derived their equation using which of the following assumption?

• Rate limiting step in the reaction is the breakdown of ES complex to product and free enzyme.   

• Rate limiting step in the reaction is the formation of ES complex.

• Concentration of the substrate can be ignored.   

• Non-enzymatic degradation of the substrate is the major step.  

Which of the following is NOT a prosthetic group of nitrate reductase?

• FAD

• Heme

• Mo

• Pterin

Which of the following acts as a branch point for the biosynthesis of sesquiterpenes and triterpenes?

• Farnesyl pyrophosphate   

• Geranyl pyrophosphate  

• Isopentyl pyrophosphate  

• Hydroxymethyl glutaryl-CoA   

Equilibrium constant (K) of non-covalent interaction between two non-bonded atoms of two different groups was measured at 27°C. It was observed that K = 100 M^-1. The strength of this non-covalent interaction in terms of Gibbs  free energy change is:

• 2746 kcal/ mol

• -2746 kcal/ mol

• 247 kcal/ mol

• -247 kcal/ mol

If van der Waals interaction is described by the following relation,

$∆{\mathrm{G}}_{\mathrm{van}} = \frac{\mathrm{A}}{{\mathrm{r}}^{12}} - \frac{\mathrm{B}}{{\mathrm{r}}^6} + \frac{{\mathrm{q}}_1{\mathrm{q}}_2}{\mathrm{r}}$

where, $∆{\mathrm{G}}_{\mathrm{van}}$is the free energy of the van der Waals interaction, A and B are constants, r is the distance between two non-bonded atoms 1 and 2, and q₁ and q₂ are partial charges on the dipoles 1 and 2. In this relation, the parameter A describes

• Electron shell attraction  

• Electron shell repulsion  

• Dipole-dipole attraction

• Dipole-dipole repulsion 

The pH of blood of a healthy person is maintained at 7.40±0.05. Assuming that this pH is maintained entirely by the bicarbonate buffer (pKa₁ and pKa₂ of carbonic acid are 6.1 and 10.3 respectively), the major ratio of [bicarbonate]/ [carbonic acid] in the blood is

• 0.05

• 1

• 10

• 20

The hydrolysis of pyrophosphate to orthophosphate is important for several biosynthetic reactions. In E. coli, the molecular mass of the enzyme pyrophosphate is 120 kD, and it consists of six identical subunits. The enzyme activity is the defined as the amount of enzyme that hydrolyzes 10µmol of pyrophosphate in 15 minutes at 37°C under standard assay condition. The purified enzyme has a V_maxof 2800 units per milligram of the enzyme. How many moles of the substrate are hydrolyzed per second per milligram of the enzyme when the substrate concentration is much greater than K_m?

• 0.05 µmol   

• 62 µmol    

• 31.1 µmol     

• 1 µmol    

Biosynthesis of tyrosine is detailed 

Shikimic acid →(A) Shikimic acid 5-phosphate →(B) C → Chorismic acid → Prephenic acid D → Transaminase NAD⁺ - NADH –CO₂ tyrosine.

Identify A, B, C and D.

• ATP, phosphoenolpyruvic acid, 3-enolpyruyl shikimic acid-5-phosphate, p-hydroxyphenyl pyruvic acid   

• GTP, pyridoxyl phosphate, 3-enolpyruvyl shikimic acid-5-phosphate, phenylpyruvic acid   

• NADP, 3-phosphohydroxypyruvic acid, 3-enolpyruvyl shikimic acid-5-phosphate, p-hydroxyphenylpyruvic acid   

• ATP, 3-phosphohydroxypyruvic acid, 3-enolpyruvyl shikimic acid-5-phosphate, pyridoxylphosphate  

Enzymes are nowadays used extensively in bioprocessing industries. Enzyme 1 is used for treatment of hides to provide a finer texture, in leather processing and manufacture of glue. Enzyme 2 is used for clarification of fruit juices.

Identify enzyme 1 and 2

• Enzyme 1- Amylase;  Enzyme 2- Pectinase

• Enzyme 1- Protease;  Enzyme 2- Amylase

• Enzyme 1- Protease;  Enzyme 2- Pectinase   

• Enzyme 1- Pectinases;  Enzyme 2- Amylase