Chemistry : Biomolecules

An electric current is passed through an aqueous solution of a mixture of alanine (isoelectric point 6.0), glutamic acid (3.2) and arginine (10. 7) buffered at pH 6. What is the fate of the three acids?

• Glutamic acid migrates to anode at pH 6. Arginine is present as a cation and migrates to the cathode. Alanine in a dipolar ion remains uniformly distributed in solution

• Glutamic acid migrates to cathode and others remain uniformly distributed in solution.

• All three remain uniformly distributed in solution.

• All three move to cathode

In aqueous solution glucose remains as 

• only in open chain form

• only in pyranose form

• only in furanose form

• n all three forms in equilbrium

A certain compound gives negative test with ninhydrin and positive test with Benedict's solution. The compound is

• a protein

• a monosaccharide

• a lipid

• an amino acid

Glucose when treated with conc. HNO₃ gives

• acetic acid

• saccharic acid

• gluconic acid

• sorbitol

The number of amino acids and number of peptide bonds in a linear tetrapeptide (made of different amino acids) are respectively.

• 4 and 4

• 5 and 5

• 5 and 4

• 4 and 3

In DNA, the consecutive deoxynucleotides are connected via

• phosphodiester linkage

• phosphomonoester linkage

• phosphotriester linkage

• amide linkage

Ribose and 2-deoxyribose can be differentiated by

• Fehling's reagent

• Tollen's reagent

• Barfoed's reagent

• Osazone formation

Which of the following reagent is used to identify fructose?

• Neutral FeCl₃

• CHCH₃/ KOH (alcohol)

• Ammonical AgNO₃

• Iodine

Which one is not a constituent of nucleic acid?

• Uracil

• Guanidine

• Phosphoric acid

• Ribose sugar

Which of the following is a peptide linkage?

• -CO-NH

• -CO-NH₂

• -CO-O-NH₄