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
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
A.
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
Amino acids exists as Zwitter ions which contain both positive and negative charge but are overall electrically neutral. At their isoelectric point, amino acids do not migrate to any electrode and remain uniformly distributed in the solution. Thus, alanine (isoelectric point 6.0) does not move to any electrode.
At a pH lower than their isoelectric point, they exist as cation and move towards cathode. Thus, arginine (isoelectric point 10. 7) exist as cation.
At a pH higher than their isoelectric point, they exist as anion and move towards anode. Thus, glutamic acid (isoelectric point 3.2) at pH 6.0 moves towards anode.
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
Which of the following reagent is used to identify fructose?
Neutral FeCl3
CHCH3/ KOH (alcohol)
Ammonical AgNO3
Iodine
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