Q.1 Which of the following is a monosaccharide?
Sucrose
Lactose
Glucose
Maltose
Explanation - Glucose is a simple sugar (monosaccharide) while sucrose, lactose, and maltose are disaccharides.
Correct answer is: Glucose
Q.2 Which bond links amino acids in a protein?
Glycosidic bond
Peptide bond
Phosphodiester bond
Hydrogen bond
Explanation - A peptide bond forms between the amino group of one amino acid and the carboxyl group of another amino acid.
Correct answer is: Peptide bond
Q.3 Which vitamin is water-soluble?
Vitamin A
Vitamin D
Vitamin E
Vitamin C
Explanation - Vitamin C is water-soluble, whereas Vitamins A, D, and E are fat-soluble.
Correct answer is: Vitamin C
Q.4 Which of the following is NOT a function of lipids?
Energy storage
Cell membrane structure
Hormone synthesis
Catalysis of biochemical reactions
Explanation - Lipids are involved in energy storage, membrane structure, and hormone synthesis, but catalysis is primarily performed by enzymes.
Correct answer is: Catalysis of biochemical reactions
Q.5 The primary structure of a protein refers to:
3D folding of polypeptide
Sequence of amino acids
Arrangement of multiple subunits
Alpha helix formation
Explanation - The primary structure is the linear sequence of amino acids in a polypeptide chain.
Correct answer is: Sequence of amino acids
Q.6 Which sugar is present in DNA?
Ribose
Deoxyribose
Glucose
Fructose
Explanation - DNA contains deoxyribose sugar, whereas RNA contains ribose.
Correct answer is: Deoxyribose
Q.7 Enzymes are primarily made of:
Lipids
Carbohydrates
Proteins
Nucleic acids
Explanation - Most enzymes are proteins that catalyze biochemical reactions.
Correct answer is: Proteins
Q.8 Which of the following is a nitrogenous base found in RNA?
Thymine
Uracil
Guanine
Cytosine
Explanation - Uracil replaces thymine in RNA molecules.
Correct answer is: Uracil
Q.9 Which polysaccharide is used for energy storage in animals?
Cellulose
Starch
Glycogen
Chitin
Explanation - Glycogen is the storage form of glucose in animals, while starch is used in plants.
Correct answer is: Glycogen
Q.10 Which amino acid has a sulfur atom in its side chain?
Methionine
Glycine
Serine
Alanine
Explanation - Methionine contains sulfur in its side chain; cysteine also contains sulfur.
Correct answer is: Methionine
Q.11 Which of the following is a structural component of cell membranes?
Triglycerides
Phospholipids
Steroids
Nucleotides
Explanation - Phospholipids form the lipid bilayer of cell membranes.
Correct answer is: Phospholipids
Q.12 Which of these is an essential fatty acid?
Oleic acid
Linoleic acid
Stearic acid
Palmitic acid
Explanation - Essential fatty acids cannot be synthesized by the body and must be obtained from diet. Linoleic acid is one of them.
Correct answer is: Linoleic acid
Q.13 Which nucleic acid carries genetic information from DNA to the ribosome?
tRNA
mRNA
rRNA
snRNA
Explanation - Messenger RNA (mRNA) carries the genetic code from DNA to ribosomes for protein synthesis.
Correct answer is: mRNA
Q.14 Which of the following is an example of a disaccharide?
Glucose
Fructose
Sucrose
Ribose
Explanation - Sucrose is a disaccharide made from glucose and fructose.
Correct answer is: Sucrose
Q.15 Which vitamin is synthesized in the skin under sunlight?
Vitamin A
Vitamin D
Vitamin E
Vitamin K
Explanation - Vitamin D is synthesized in the skin when exposed to UV light from sunlight.
Correct answer is: Vitamin D
Q.16 Which of the following amino acids is aromatic?
Lysine
Phenylalanine
Serine
Leucine
Explanation - Phenylalanine has a benzene ring in its side chain, making it aromatic.
Correct answer is: Phenylalanine
Q.17 Which polysaccharide provides structural support in plants?
Starch
Glycogen
Cellulose
Chitin
Explanation - Cellulose forms the rigid structure of plant cell walls.
Correct answer is: Cellulose
Q.18 Which of the following is a purine base?
Adenine
Cytosine
Thymine
Uracil
Explanation - Adenine and guanine are purines; cytosine, thymine, and uracil are pyrimidines.
Correct answer is: Adenine
Q.19 Which of the following biomolecules contains phosphorus?
Lipids
Proteins
Nucleic acids
Carbohydrates
Explanation - Nucleic acids contain a phosphate group in their backbone.
Correct answer is: Nucleic acids
Q.20 Which amino acid is considered acidic?
Aspartic acid
Lysine
Serine
Valine
Explanation - Aspartic acid has a carboxyl group in its side chain that makes it acidic.
Correct answer is: Aspartic acid
Q.21 Which of these lipids is a steroid?
Cholesterol
Triglyceride
Phosphatidylcholine
Oleic acid
Explanation - Steroids have a four-ring structure; cholesterol is a common example.
Correct answer is: Cholesterol
Q.22 Which vitamin is important for blood clotting?
Vitamin A
Vitamin D
Vitamin E
Vitamin K
Explanation - Vitamin K is essential for the synthesis of clotting factors in the blood.
Correct answer is: Vitamin K
Q.23 Which sugar is found in RNA but not DNA?
Glucose
Ribose
Deoxyribose
Fructose
Explanation - RNA contains ribose, whereas DNA contains deoxyribose.
Correct answer is: Ribose
Q.24 Which of the following is an essential amino acid?
Alanine
Leucine
Serine
Aspartic acid
Explanation - Leucine cannot be synthesized by the body and must be obtained from the diet.
Correct answer is: Leucine