Question

m ical reactions 8) Which of the following represents an amino acid in a basic solution (pH-11)? A) R-CH-COOR -CH-COOH ENH2 R--CH-COOH R-CH-coo C) NH3 D) 3NH3 9) Which of the following is a zwitterion? B) NH2 R-CH-Coo E) NH2 A) R-CH-COO R-ch-cool R-ca-cooH R-ch-coo H2B) NH2C) NH3 D) NH3 R-ca-coo E) NH2 10) Which of the following amino acids has the lowest isoelectric point? A) glutamic acid B) lysine C) valine D) glycine E) methionine 11) Calculate the isoelectric point for the following compound: X-CH-CH 8-9 PK, 2.19 он н, PK, = 4 25 pka = 9.67 A) 3.22 E) 9.67 B) 5.34 C) 5.93 D) 6.91 12) What is electrophoresis? A) a technique that separates amino acids on the basis of their polarity B) a technique that separates amino acids on the basis of their solubility in water C) a technique that separates amino acids on the basis of their pl values D) a technique that separates amino acids on the basis of pka of -COOH values E) a technique that separates amino acids on the basis of pka of a-+NH3 values 13) What is thin-layer chromatography? A) a technique that separates amino acids on the basis of their polarity B) a technique that separates amino acids on the basis of their charge C) a technique that separates amino acids on the basis of their pl values D) a technique that separates amino acids on the basis of pKa of -COOH values E) a technique that separates amino acids on the basis of pKa of a-+NH3 values

Answer 1

reactions R-CH-COO R-CH-COOH A) following represents an amino acid in a basic solution (pH = 11)? lution (pH = 11)? E, at basic phu E, at basic pH the -COOH and NH3+ both protons R-CH-COOH R-CH-Coor -ch-C00 ONH2 are lost to give B) NH2 C) NH3 D) NH3 )NH2 monoanionic structure. 9) Which of the following is a zwitterion? A) option D R-CH-COOH R-CH-COOH R-CH A Zwitterion is the species with both +ve and -ve charges but net charge is zero. 2 B) NH2 c) @NH3 D) ONGE) 10) Which of the following amino acids has the lowest isoelectric point? A) glutamic acid B) lysine C) valine D) glycine E) glutamic acid with acidic side 11) Calculate the isoelectric point for the following compound: chain has lowest pl of about 3 H X-CH-CH & PK = 219 HO NH, OH PI = 1/2[sum of pKa of similarly ionising groups] = 1/2[ 219+4.25] =3.22 PK, = 425 pka = 9.67 A) 3.22 B) 5.34 C) 5.93 D) 6.91 E) 9.67 12) What is electrophoresis? A) a technique that separates amino acids on the basis of their polarity B) a technique that separates amino acids on the basis of their solubility in water C) a technique that separates amino acids on the basis of their pl values D) a technique that separates amino acids on the basis of pka of -COOH values E) a technique that separates amino acids on the basis of pKa of a-+NH3 values 13) What is thin-layer chromatography? A) a technique that separates amino acids on the basis of their polarity B) a technique that separates amino acids on the basis of their charge C) a technique that separates amino acids on the basis of their pl values D) a technique that separates amino acids on the basis of pka of a-COOH values E) a technique that separates amino acids on the basis of pKa of a-+NH3 values