Biochemistry-I MCQs | BIO202 MCQs | Set 3
Biochemistry-I MCQs | BIO202 MCQs | Set 3
MCQs (Multiple Choice Questions)
1) Oxy hemoglobin dissociation curve describe the relationship of _________.
a) Available Oxygen
b) Amount of carbon dioxide carried by hemoglobin
c) Fibrinogen
d) Oxy-hemoglobin curve stability
Correct Answer:
The correct answer is 'a'.
Explanation:
The oxyhemoglobin dissociation curve describes the relationship between the available oxygen and the oxygen saturation of hemoglobin in the blood. It illustrates how hemoglobin's affinity for oxygen changes with varying oxygen partial pressures, showing how readily hemoglobin binds and releases oxygen in response to changes in oxygen levels. This relationship is essential in understanding how oxygen is transported and delivered to tissues throughout the body.
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2) Which one of the following is made up of two molecules of glucose?
a) Maltose
b) Starch
c) Cellulose
d) Amylose
Correct Answer:
The correct answer is 'a'.
Explanation:
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3) Which bond exists between the carbonyl group and oxygen of a hydroxyl group in ring structure of glucose?
b) Covalent
d) both ionic and covalent
Correct Answer:
The correct answer is 'b'.
Explanation:
The bond that exists between the carbonyl group (C=O) and the oxygen of a hydroxyl group (OH) in the ring structure of glucose is a covalent bond. This specific covalent bond is called a glycosidic bond, and it forms as a result of a condensation reaction between the hydroxyl groups.
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4) In Benedict test, the formation of cuprous oxide is indicated by the formation of ____________.
a) blue ppt
b) silver mirror
c) red ppt
d) none of these
Correct Answer:
The correct answer is 'c'.
Explanation:
In the Benedict test for reducing sugars, the formation of cuprous oxide, which is a red brown precipitate, is indicated by the formation of a red ppt. This color change is used as a qualitative test for the presence of reducing sugars such as glucose.
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5) Glucose 6 Phosphate is formed by the addition of phosphate group to C6 of glucose by __________ linkage.
a) Ether
b) Ester
c) Ionic
d) none of these
Correct Answer:
The correct answer is 'b'.
Explanation:
Glucose 6-phosphate is formed by the addition of a phosphate group to the carbon-6 (C6) of glucose through an ester linkage. This ester linkage is a covalent bond formed between the phosphate group and the hydroxyl group on the glucose molecule.
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6) E. coli convert lactose of milk to lactic acid by action of _________.
a) Beta galactosidase
b) Amyloglucosidase
c) Alpha amylase
d) Maltase
Correct Answer:
The correct answer is 'a'.
Explanation:
E. coli converts lactose in milk to lactic acid through the action of an enzyme called beta galactosidase. This enzyme hydrolyzes lactose into its constituent sugars, glucose and galactose, which can then be metabolized further to produce lactic acid.
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7) At any pH above pI, gycine has a net ______ charge and will move towards the _______.
a) negative, anode
b) negative, cathode
c) positive, anode
d) positive, cathode
Correct Answer:
The correct answer is 'c'.
Explanation:
Glycine is an amino acid with a pKa (the pH at which it is electrically neutral) close to its isoelectric point (pI). The pI of an amino acid is the pH at which the amino acid carries no net charge.
At any pH value above its pI, glycine will be in its deprotonated form, which has a net positive charge. In electrophoresis, charged molecules move toward the electrode with the opposite charge. Since glycine is positively charged at pH values above its pI, it will migrate toward the anode (the positively charged electrode).
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8) Which of the following amino acids contain two COOH groups?
a) Alanine
b) Glutamate
c) Glycine
d) Valine
Correct Answer:
The correct answer is 'b'.
Explanation:
Glutamate is an amino acid that contains two carboxyl (COOH) groups. This characteristic makes it an acidic amino acid.
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9) Which of the following amino acid is positively charged at physiological pH?
a) Lysine
b) Aspartate
c) Tyrosine
d) Alanine
Correct Answer:
The correct answer is 'a'.
Explanation:
Lysine is positively charged at physiological pH. It has an amino group (NH2) in its side chain that can become protonated, giving it a positive charge under these conditions.
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10) Peptide bond is ___________ linkage between two amino acids.
a) Ester
b) Amide
c) Ether
d) None of these
Correct Answer:
The correct answer is 'b'.
Explanation:
A peptide bond is an amide linkage between two amino acids. It is a covalent bond that forms between the amino group (NH2) of one amino acid and the carboxyl group (COOH) of another amino acid during the process of protein synthesis.
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