CHEMISTRY MCQs (PART 3)

CHEMISTRY MCQs (PART 3)

85. Optically active compounds are capable of

(A) Different reactions

(B) Rotating plane of polarized light

(C) Showing same chemical properties

(D) None of these

86. The reference compound for absolute configuration of optically active compound is

(A) Alanine

(B) Lactic acid

(C) Glyceraldehyde

(D) Dihydroxy acetone

87. All the standard amino acids except the following have one chiral ‘c’ atom:

(A) Threonine, Isoleucine

(B) Isoleucine, Alanine

(C) Threonine, Alanine

(D) Alanine, Glutamine

88. The role of complement proteins:

(A) Defense

(B) Helps immunity of the body

 (C) Not predicatable

(D) None of these

89. Optical isomers that are mirror images and non superimposable are called

(A) Diastereomers

(B) Euantiomers

(C) dl isomers

(D) Stereomers

90. Living cells have the unique ability to synthesize only _________ the form of optical isomer due to _________.

(A) ‘d’ form, stereospecific enzymes

(B) ‘l’ form stereospecific enzymes

(C) ‘d’ form, DNA

(D) ‘L’ form, DNA

91. Isoelectric pH of an amino acid is that pH at which it has a

(A) Positive charge

(B) Negative charge

 (C) No net charge

(D) All of these

92. Albuminoids are similar to

(A) Albumin

(B) Globulin

(C) Both A and B

(D) None of these

93. Abnormal chain of amino acids in sickle cells anaemia is

(A) Alpha chain

(B) Beta chain

 (C) Gama chain

(D) Delta chain

94. In prehepatic jaundice, protein flocculation test is

(A) Normal/weekly positive

(B) Usually positive

(C) Negative

(D) None of these

95. Side chains of all amino acids contain aromatic rings except

(A) Pheynl alanine

(B) Alanine

(C) Tyrosine

(D) Tryptophan

96. In Nitroprusside test, amino acid cystein produces

 (A) Blue colour complex

(B) Red colour

(C) Yellow colour

(D) Purple colour

97. Bonds that are formed between two cysteine residues is

(A) Disulphide

(B) Peptide

(C) Electrostatic

 (D) Hydrophobic

98. The acid amide of Aspartic acid is

(A) Glutamine

(B) Arginine

 (C) Aspargine

 (D) Ornithine

99. It is the only amino acid having an ionizing ‘R’ group with a pK’ near 7 and is important in the active site of some enzymes:

(A) Arginine

(B) Cystein

(C) Cystine

(D) Histidine

100. Hemoglobin has a high content of this amino acid:

(A) Proline

(B) Leucine

(C) Arginine

(D) Histicline

101. A hexa peptide with 5 aspartic acid would have a net charge at pH 7:

(A) Neutral

(B) Positive

(C) Negative

(D) Not predictable

102. In the genetic disorder of cystinuria, the patient excretes large quantities of cystine in their urine and its low solubility causes crystalline cystine to precipitate as stones in kidneys. The remedy involves

ingesting Na HCO3. Reaction of this treatment is

(A) NaHCO2 combines with cystine

(B) NaHCO3 raises the pH above the isoelectric point of cystine

(C) NaHCO3 prevents stone formation by hydrolysis of cystine to cysteine

(D) None of these

103. In the following reaction, Alanine acts as a 3 3 3 3 + + → H H | | H N – – COO —— H N – – COOH C C | | CH CH

(A) Acid

(B) Base

(C) Zwitter ion

(D) None of these

104. Amino acids excepting histidine are not good buffering agents in cell because

(A) They exist as zwitter ions

 (B) Their pk and not in the physiological pH of a cell

(C) Only Histidine has pk of its R group at 6.0 unlike the others which have at a different pH

(D) None of these

105. At neutral pH Alanine has the following structure:

(A) − − 2 3 H H N C COOH CH

(B) + 3 − − 3 H H N C COO CH

(C) 2 − − 3 H H N C COO CH

(D) + 2 − − 3 H H N C COO CH

106. The amino acids in which the R groups have a net positive charge at pH 7.0 are

(A) Lysine, Arginine, Histidine

(B) Lysine, Aspargine

(C) Histidine, Aspargine

(D) Glutamine, Arginine

107. Apolipoproteins are

(A) AI

(B) AI1

(C) C1

(D) All of these

108. The amino acid which has a pK near 4 and thus is negatively charged at pH 7 is

(A) Alanine

(B) Glutamic acid

(C) Glutamine

(D) Aspargine

109. The side chain of which of the following amino acid contain sulphur atom?

(A) Methionine

(B) Threonine

(C) Leucine

(D) Tryptophan

110. Which of the followings gives a positive test for Ninhydrin?

(A) Reducing sugars

(B) Triglycerides

(C) Alpha aminoacids

(D) Esterified Fats

111. In glutathione (a tripeptide) is present apart from Glutamic acid and cysteine:

(A) Serine

(B) Glycine

(C) Leucine

(D) Phenyl alanine

112. 2-Amino 3-OH propanoic acid is

(A) Glycine

(B) Alanine

(C) Valine

(D) Serine

113. All amino acids have one asymmetric carbon atom, except

(A) Arginine

(B) Aspargine

(C) Histidine

(D) Glycine

114. Number of amino acids present in the plant, animal and microbial proteins:

 (A) 20

(B) 80

 (C) 150

(D) 200

115. Immunoglobulins are characterized by their

(A) Heavy chains

(B) Molecular weight

(C) Light chains

(D) Electrophoretic behavior

116. The bond in proteins that is not hydrolysed under usual conditions of denaturation:

(A) Hydrophobic bond

(B) Hydrogen bond

(C) Disulphide bond

(D) Peptide bonds

117. If the amino group and a carboxylic group of the amino acid are attached to same carbon atom, the amino acid is called

(A) Alpha

(B) Beta

(C) Gamma

(D) Delta

118. Zymogen is

(A) An intracellular enzyme

(B) Serum enzyme

(C) A complete extracellular enzyme

(D) An inactivated enzyme

119. SGOT level in a adult is

 (A) 5–40 units/dl

(B) 1–4 units/dl

(C) 5–15 units/dl

(D) 50–100 units/dl

120. Activity of ceruloplasmin shown in vitro:

 (A) Reductase

 (B) Hydrolase

 (C) Ligase

 (D) Oxidase

121. Increased serum alanine during fasting is due to

(A) Breakdown of muscle proteins

(B) Decreased utilization of non essential amino acids

(C) Leakage of aminoacids to plasma

(D) Impaired renal function

122. The following 4 amino acids are required for completion of urea cycle except

(A) Aspartic acid

(B) Arginine

(C) Ornithine

(D) Glycine

123. Number of amino acids present in the dietary proteins:

(A) 22

(B) 23

 (C) 20

(D) 19

124. Urea synthesis takes place in

(A) Blood

(B) Liver

 (C) Kidney

(D) Heart

125. All followings are ketogenic aminoacids except

(A) Leucine

(B) Isoleucine

(C) Phenyl alanine

 (D) Glycine

126. The amino acid containing an indole ring:

(A) Tryptophan

(B) Arginine

(C) Threonine

(D) Phenylalanine

127. Histidine is converted to histamine through the process of

 (A) Transamination

(B) Decarboxylation

(C) Oxidative deamination

(D) Urea cycle