Biomolecules NEET Previous Year Questions (PYQs)
Practice NEET previous year questions from Biomolecules. These chapter-wise MCQs cover carbohydrates, proteins, nucleic acids, vitamins and enzymes with answers and clear explanations.
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Biomolecules Chapter Notes
Q1. The non-essential amino acid among the following is:
(NEET 2019)
- (A) Lysine
- (B) Valine
- (C) Leucine
- (D) Alanine
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(D)
Show Explanation
Alanine is non-essential as it can be synthesised by the human body.
Q2. Which structure of protein remains intact during denaturation?
(Odisha NEET 2019)
- (A) Secondary structure
- (B) Tertiary structure
- (C) Primary structure
- (D) Quaternary structure
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(C)
Show Explanation
Denaturation disrupts secondary and tertiary structures but does not affect the primary structure.
Q3. The difference between amylose and amylopectin is:
(NEET 2018)
- (A) Amylose is branched
- (B) Amylopectin has α(1→4) and α(1→6) linkages
- (C) Amylose has α(1→6) linkage
- (D) Amylose contains galactose
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(B)
Show Explanation
Amylopectin is a branched polymer with both α(1→4) and α(1→6) glycosidic bonds.
Q4. Which compound can exist as a zwitter ion?
(NEET 2018)
- (A) Aniline
- (B) Acetanilide
- (C) Benzoic acid
- (D) Glycine
Show Answer
(D)
Show Explanation
Amino acids like glycine contain both –NH₃⁺ and –COO⁻ groups.
Q5. Which statement is NOT correct?
(NEET 2017)
- (A) Ovalbumin is a protein in egg white
- (B) Thrombin and fibrinogen are involved in clotting
- (C) Denaturation increases protein activity
- (D) Insulin regulates blood sugar
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(C)
Show Explanation
Denaturation destroys biological activity of proteins.
Q6. Genetic information flows according to central dogma as:
(NEET 2016)
- (A) RNA → DNA → Protein
- (B) DNA → RNA → Protein
- (C) Protein → RNA → DNA
- (D) RNA → Protein → DNA
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(B)
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Central dogma states DNA is transcribed to RNA and translated into protein.
Q7. The sugar present in RNA and DNA respectively is:
(NEET 2016)
- (A) Arabinose and ribose
- (B) Ribose and 2-deoxyribose
- (C) Ribose and arabinose
- (D) Deoxyribose and ribose
Show Answer
(B)
Show Explanation
RNA contains ribose, while DNA contains 2-deoxyribose.
Q8. Which of the following is a non-reducing sugar?
(NEET 2016)
- (A) Glucose
- (B) Maltose
- (C) Lactose
- (D) Sucrose
Show Answer
(D)
Show Explanation
Sucrose has no free aldehyde or ketone group.
Q9. Which hormone is released during stress and stimulates glycogenolysis?
(NEET 2014)
- (A) Thyroxine
- (B) Insulin
- (C) Adrenaline
- (D) Estradiol
Show Answer
(C)
Show Explanation
Adrenaline is known as the fight-or-flight hormone.
Q10. In proteins, amino acids are linked by:
(NEET 2016)
- (A) Glycosidic bond
- (B) Peptide bond
- (C) Hydrogen bond
- (D) Phosphodiester bond
Show Answer
(B)
Show Explanation
A peptide bond forms between –COOH and –NH₂ groups.
Q11. Which vitamin deficiency causes osteomalacia?
(NEET 2020)
- (A) Vitamin A
- (B) Vitamin D
- (C) Vitamin K
- (D) Vitamin E
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(B)
Show Explanation
Vitamin D deficiency causes softening of bones.
Q12. Which of the following is NOT a fat-soluble vitamin?
(NEET 2011)
- (A) Vitamin A
- (B) Vitamin B complex
- (C) Vitamin D
- (D) Vitamin E
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(B)
Show Explanation
Vitamin B complex is water soluble.
Q13. Complementary base pairs in DNA are:
(NEET 2008)
- (A) A–G and T–C
- (B) A–U and G–C
- (C) A–T and G–C
- (D) A–T and G–U
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(C)
Show Explanation
Adenine pairs with thymine, guanine with cytosine.
Q14. Which hormone contains iodine?
(NEET 2009)
- (A) Insulin
- (B) Testosterone
- (C) Thyroxine
- (D) Adrenaline
Show Answer
(C)
Show Explanation
Thyroxine is an iodine-containing hormone.
Q15. Enzymes are:
(NEET 2002)
- (A) Carbohydrates
- (B) Lipids
- (C) Proteins with specific structure
- (D) Vitamins
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(C)
Show Explanation
Enzymes are protein biocatalysts.
Q16. Cell membranes are mainly composed of:
(NEET 2005)
- (A) Proteins
- (B) Fats
- (C) Phospholipids
- (D) Carbohydrates
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(C)
Show Explanation
Phospholipids form the bilayer structure of membranes.
Q17. The sweetest sugar is:
(NEET 1999)
- (A) Glucose
- (B) Sucrose
- (C) Fructose
- (D) Maltose
Show Answer
(C)
Show Explanation
Fructose has the highest sweetness index.
Q18. The helical structure of protein is stabilised by:
(NEET 2004)
- (A) Peptide bonds
- (B) Hydrogen bonds
- (C) Ionic bonds
- (D) Disulphide bonds
Show Answer
(B)
Show Explanation
α-Helix is stabilised by hydrogen bonding.
Q19. On hydrolysis of starch, the final product obtained is:
(NEET 1991)
- (A) Fructose
- (B) Glucose
- (C) Sucrose
- (D) Maltose
Show Answer
(B)
Show Explanation
Complete hydrolysis of starch yields glucose.
Q20. Which of the following is a biopolymer?
(NEET 1994)
- (A) Nylon-6,6
- (B) Teflon
- (C) Neoprene
- (D) DNA
Show Answer
(D)
Show Explanation
DNA is a naturally occurring polymer.
👉 More Biomolecules NEET PYQs will be added gradually.