Explore topic-wise MCQs in Biochemistry.

This section includes 132 Mcqs, each offering curated multiple-choice questions to sharpen your Biochemistry knowledge and support exam preparation. Choose a topic below to get started.

1.

When the amino acid alanine (R-group is CH) is added to a solution with a pH of 7.3, alanine becomes

A. a cation
B. nonpolar
C. a zwitterions
D. an isotope
Answer» D. an isotope
2.

The sulphur containing side chain of cysteine is

A. ampiphillic, highly reactive and capable of reacting with another cysteine
B. hydrophillc, highly reactive and capable of reacting with another cysteine
C. hydrophobic, highly reactive and capable of reacting with another cysteine
D. none of the above
Answer» D. none of the above
3.

The sequence of letters 'WYQN' will represent

A. Tryptophan, tyrosine, glutamic acid, asparagine
B. Tryptophan, tyrosine, glutamine, asparagine
C. Tryptophan, glutamine, tryptophan, asparagine
D. Glutamine, tyrosine, tryptophan, aspartic acid
Answer» C. Tryptophan, glutamine, tryptophan, asparagine
4.

An intermediate of the citric acid cycle that undergoes reductive amination with glutamine as nitrogen donor is

A. α-ketoglutarate
B. Glutamine
C. NADPH
D. H⁺
Answer» B. Glutamine
5.

Phosphorylation of AMP to ADP is promoted by

A. Adenylate kinase
B. Aspartate transcarbamoylase
C. Dihyhroorotase
D. Cytidylate synthase
Answer» B. Aspartate transcarbamoylase
6.

A second amino group is transferred to cituilline from

A. Aspartate
B. Glutamate
C. Alanine
D. Guanine
Answer» B. Glutamate
7.

The cyclized derivative of glutamate is

A. Proline
B. Arginine
C. Glutamine
D. Serine
Answer» B. Arginine
8.

Which of the following produce pyruvate?

A. Leucine
B. Isoleucine
C. Lysine
D. Alanine
Answer» E.
9.

Which of the following is a non-essential amino acid?

A. Methionine
B. Threonine
C. Lysine
D. Cysteine
Answer» E.
10.

Glutamine is converted to glutamate and NH₄⁺ by

A. Amino transferases
B. Glutaminase
C. Glutamine synthase
D. Glutamate dehydrogenase
Answer» C. Glutamine synthase
11.

Nitrogen atoms of urea produced in the urea cycle are derived from

A. Ammonia and aspartic acid
B. Nitrate
C. Nitrite
D. Ammonia
Answer» B. Nitrate
12.

Pyridoxal phosphate and its aminate form, pyridoxamine phosphate are tightly bound coenzymes of

A. Amino transferases
B. Glutaminase
C. Glutamine synthase
D. Glutamate dehydrogenase
Answer» B. Glutaminase
13.

Conversion of dUMP to dTMP is catalyzed by

A. Thymidylate synthase
B. Dihydrofolate reductase
C. Dihyhroorotase
D. Cytidylate synthase
Answer» B. Dihydrofolate reductase
14.

The carbon atom source while producing urea in the urea cycle is

A. CO₂
B. Glucose
C. Aspartic acid
D. Arginine
Answer» B. Glucose
15.

The first intermediate in cholesterol synthesis is

A. Mevalonate
B. Isoprene
C. Squalene
D. Ethylene
Answer» B. Isoprene
16.

Generally the receptors for steroid hormones reside at

A. Nucleoplasm
B. Nuclear membrane
C. Cytoplasm
D. Plasma membrane
Answer» B. Nuclear membrane
17.

Conversion of nitrogen to ammonia or nitrogenous compounds is termed as

A. Nitrogen fixation
B. Nitrification
C. Denitrification
D. Nitrogen assimilation
Answer» B. Nitrification
18.

3-phosphoglycerate is not the metabolic precursor for

A. Serine
B. Glycine
C. Cysteine
D. Arginine
Answer» E.
19.

Which of the following yield acetyl co-A via aceto-acetyl co-A?

A. Leucine
B. Isoleucine
C. Threonine
D. Alanine
Answer» B. Isoleucine
20.

Free ammonia combined with glutamate to yield glutamine by the action of

A. Glutaminase
B. Glutamine synthase
C. Glutamate dehydrogenase
D. Amino transferase
Answer» C. Glutamate dehydrogenase
21.

Lignin is derived from

A. Phenylalanine
B. Valine
C. Tryptophan
D. Arginine
Answer» B. Valine
22.

The first enzyme in the pathway carbamoyl phosphate synthase I, is allosterically activated by

A. N-acetylglutamate
B. Acetyl coA
C. Glutamate
D. Carbamoyl phosphate
Answer» B. Acetyl coA
23.

Glutamate is metabolically converted to α-ketoglutarate and NH₄⁺ by a process

A. Oxidative deamination
B. Transamination
C. Reductive deamination
D. Deamination
Answer» B. Transamination
24.

Which of the following is the integral membrane protein of smooth ER?

A. Thiolase
B. HMG co-A synthase
C. HMG co-A reductase
D. Pyruvate kinase
Answer» D. Pyruvate kinase
25.

Which of the following gives rise to methionine, threonine and lysine?

A. Pyruvate
B. Glutamate
C. Aspartate
D. Serine
Answer» D. Serine
26.

The branched chain amino acid is not

A. Leucine
B. Isoleucine
C. Valine
D. Alanine
Answer» E.
27.

The first amino group entering into urea cycle is

A. Carbomyl phosphate
B. Ornithine
C. Cituilline
D. Argininosuccinate
Answer» B. Ornithine
28.

The first step in the catabolism of most L-amino acids once they have reached the liver is promoted by

A. Amino transferases
B. Glutaminase
C. Glutamine synthase
D. Glutamate dehydrogenase
Answer» B. Glutaminase
29.

The necessary coenzyme for transamination reactions is

A. Pyridoxal phosphate
B. Thiamine pyrophosphate
C. NAD
D. Coenzyme A
Answer» B. Thiamine pyrophosphate
30.

Which of the following are exclusively glucogenic?

A. Arginine
B. Leucine
C. Lysine
D. Threonine
Answer» B. Leucine
31.

The reaction of glutamate and NH₄⁺ to yield glutamine is catalyzed by

A. Uridylyltransferase
B. Adenylyltransferase
C. Glutamate synthase
D. Glutamine synthase
Answer» E.
32.

Which of the following yield acetyl coA directly?

A. Phenylalanine
B. Isoleucine
C. Lysine
D. Alanine
Answer» C. Lysine
33.

Almost 85 % of produced millions of tones of ammonia (NH₃) is used for making

A. glass
B. fertilizers
C. urea
D. nitrogen
Answer» C. urea
34.

Steroids have ______________

A. Sterol nucleus with two alkyl chain attached to the ring D of cholesterol
B. Sterol nucleus with two CH₃ between C and D ring and A and B ring of cholesterol
C. Sterol nucleus without CH₃ between C ring and D ring of cholesterol
D. Sterol nucleus but lack the alkyl chain attached to the ring D of cholesterol
Answer» E.
35.

Which of the following is a PLP-requiring enzyme?

A. Ornithine decarboxylase
B. Glutathione peroxidase
C. Glutamine synthase
D. Glutamate synthase
Answer» B. Glutathione peroxidase
36.

Formation of organic nitrogen compounds like amino acids from inorganic nitrogen compounds is called as

A. Nitrogen fixation
B. Nitrification
C. Denitrification
D. Nitrogen assimilation
Answer» E.
37.

How many carbons are present in geranyl pyrophosphate?

A. 8
B. 9
C. 10
D. 11
Answer» D. 11
38.

A person suffering from phenylketonuria on consumption food containing high phenylalanine may lead to the accumulation of

A. phenylalanine
B. phenylpyruvate
C. tyrosine
D. isoleucine
Answer» C. tyrosine
39.

Transamination is the transfer of an amino

A. acid to a carboxylic acid plus ammonia
B. group from an amino acid to a keto acid
C. acid to a keto acid plus ammonia
D. group from an amino acid to a carboxylic acid
Answer» C. acid to a keto acid plus ammonia
40.

Histidine is degraded to α-ketoglutarate and is described as a

A. gluco amino acid
B. glucogenic amino acid
C. ketogenic amino acid
D. keto-gluco amino acid
Answer» C. ketogenic amino acid
41.

Which of the following is degraded to methylmalonylsemialdehyde?

A. Glutamine
B. Tyrosine
C. Thymine
D. Leucine
Answer» D. Leucine
42.

Which of the following produce oxaloacetate?

A. Aspartate
B. Isoleucine
C. Threonine
D. Alanine
Answer» B. Isoleucine
43.

Which of the following gives rise to γ-amino butyrate?

A. Glutamate synthase
B. Glutamate decarboxylation
C. Glutamine synthase
D. Pyruvate decarboxylation
Answer» C. Glutamine synthase
44.

Glutathione peroxidase contains a covalently bound

A. Selenium atom
B. Calcium atom
C. Magnesium atom
D. Copper atom
Answer» B. Calcium atom
45.

Which of the following is the precursor for auxin?

A. Phenylalanine
B. Valine
C. Tryptophan
D. Arginine
Answer» D. Arginine
46.

Which of the following is not an aromatic amino acid?

A. Phenylalanine
B. Tyrosine
C. Tryptophan
D. Leucine
Answer» E.
47.

Tyrosine gives rise to a family of catecholamines that does not include

A. Dopamine
B. Norepinephrine
C. Epinephrine
D. Cortisol
Answer» E.
48.

The reaction vessel of ammonia (NH₃) production is composed of

A. 400-500 temperature
B. 25-300 atm pressure
C. iron
D. all of above
Answer» E.
49.

Nitric acid (HNO₃) is made from

A. ammonium
B. nitrogen
C. nitrate
D. ammonia
Answer» E.
50.

In car engine, the fuel is in compressed form and ignited by

A. key
B. spark
C. accelerator
D. brake
Answer» C. accelerator