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NEET MCQs On Biomolecules

DEEKSHA August 24, 2025

Biomolecules – NEET Concepts, MCQs & Quick Reminder| Class 11 NCERT

Within cells, biomolecules are in charge of control, information transfer, energy, and structure. Because the questions in this chapter are fact-based and straightforward, it is crucial for NEET. Let's take it one step at a time!
 
NEET MCQs On Biomolecules

Biomolecule Classification

There are four major groups of biomolecules found in living matter:
1. Carbohydrates: sources of energy (rice, sugar, 🍞).
2. Proteins: Enzymes, hormones, and muscles for bodybuilders and workers.
3. Lipids: Membranes and stored energy (oils, fats).
4. Genetic information is contained in nucleic acids (DNA, RNA).

Types of carbohydrates (sugars):

 Simple sugars, or monosaccharides, are:  fructose, galactose, and glucose.
 Lactose (glucose + galactose), maltose (glucose + glucose), and sucrose (glucose + fructose) are examples of disaccharides.
 Polysaccharides include chitin, cellulose, glycogen, and starch.

 Idea  Remember:

  •  Plants use starch as a storage material. 
  •  In mammals, glycogen is a storage form. 
  •  Plant cell wall → cellulose
  •  Chitin → insect exoskeleton

The proteins

composed of 20 different types of amino acids.
Peptide linkages hold them together.

 Structure levels:

  •  First (sequence)
  •  Secondary (β-sheet, α-helix)
  •  Three-dimensional (3D) folding
  •  Multiple polypeptides, such as hemoglobin, are quaternary.
  •  Concept Reminder:
  •  Proteins are mostly enzymes (biocatalysts).
  •  Structural proteins include collagen and keratin.
  •  Hormonal proteins: glucagon, insulin.

Lipids

Not polymers but important biomolecules.
Types:
  • Fats & oils (triglycerides = glycerol + fatty acids).
  • Phospholipids (plasma membrane structure).
  • Steroids (cholesterol, testosterone, estrogen).

Concept Reminder:

  • Phospholipids form lipid bilayer → cell membrane.
  • Cholesterol stabilizes membrane fluidity.
  • Unsaturated fats = liquid oils (double bonds).
  • Saturated fats = solid at room temperature (no double bonds).

The Nucleic Acids

Deoxyribonucleic acid, or DNA, is the genetic blueprint.
Ribonucleic acid, or RNA, aids in the creation of proteins.
Base + sugar + phosphate equals nucleotides.

Bases of nitrogen:

Purines produce guanine (G) and adenine (A).
Cytosine (C), Thymine (T in DNA), and Uracil (U in RNA) are examples of pyrimidines.

Concept Reminder:

  • According to Chargaff's Rule, A = T, G = C.
  • Watson and Crick (1953) described DNA as a double helix.
  • tRNA → transfer, rRNA → ribosome, and mRNA → messenger.

The biological catalysts are enzymes.

With the exception of ribozymes, which are RNA, nearly all enzymes are proteins.
Function: Reduce activation energy to speed up biological activities.
Features: Extremely focused.
function optimally at the ideal pH and temperature.
Follow the kinetics of Michaelis-Menten.
 

Concept Reminder:

  • Enzyme-substrate complex is equal to enzyme plus substrate.
  • For instance:
  • Amylase breaks down starch.
  • Pepsin → stomach digestion of proteins.
  • DNA replication → DNA polymerase.
  • Methods of Analysis (NEET Special)
  • Chromatography → biomolecule separation.
  • Cell organelles are separated by centrifugation.
  • Electrophoresis → Analysis of proteins and DNA.

MCQs with Concept Reminders

Q1. Which polysaccharide is the main storage in animals?
A) Starch
B) Glycogen 
C) Cellulose
D) Chitin
Answer : B) Glycogen
Reminder: “Animal starch” = Glycogen.

Q2. Which of the following is a disaccharide?
A) Glucose
B) Maltose 
C) Starch
D) Cellulose
Answer : B) Maltose 
Reminder: Di = two monosaccharides → Maltose = Glucose + Glucose.

Q3. The structural polysaccharide in plant cell wall is:
A) Starch
B) Glycogen
C) Cellulose 
D) Inulin
Answer : C) Cellulose 
Reminder: Cellulose = β-glucose chains.

Q4. The bond linking amino acids in proteins is:
A) Hydrogen bond
B) Ionic bond
C) Peptide bond 
D) Phosphodiester bond
Answer : C) Peptide bond
Reminder: Amino acid – COOH joins NH2 → Peptide bond.

Q5. Which vitamin is cholesterol a precursor for?
A) Vitamin C
B) Vitamin A
C) Vitamin D 
D) Vitamin E
Answer : C) Vitamin D 
Reminder: Sunlight + cholesterol → Vitamin D synthesis.

Q6. Which nitrogen base is present in RNA but not DNA?
A) Adenine
B) Guanine
C) Uracil 
D) Thymine
Answer : C) Uracil
Reminder: RNA = A, U, G, C.

Q7. Enzyme responsible for DNA replication is:
A) RNA polymerase
B) DNA polymerase 
C) Ligase
D) Helicase
Answer : B) DNA polymerase
Reminder: DNA polymerase → DNA synthesis.

Q8. Which lipid forms the main framework of plasma membrane?
A) Steroid
B) Phospholipid 
C) Glycolipid
D) Triglyceride
Answer : B) Phospholipid
Reminder: Membranes = Phospholipid bilayer.

Q9. The rule A=T and G=C was given by:
A) Watson & Crick
B) Chargaff 
C) Franklin
D) Pauling
Answer : B) Chargaff 
Reminder: Chargaff’s rule for DNA pairing.

Q10. Which of the following is NOT a protein?
A) Insulin
B) Hemoglobin
C) Keratin
D) Cellulose 
Answer : D) Cellulose
Reminder: Cellulose = polysaccharide, not protein.

Q11. The most abundant biomolecule on Earth is:
A) Protein
B) DNA
C) Cellulose 
D) Starch
Answer : C) Cellulose 
Reminder: Plant cell wall = cellulose → most abundant organic compound.

Q12. The most abundant protein in the animal world is:
A) Myosin
B) Collagen 
C) Keratin
D) Hemoglobin
Answer : B) Collagen
Reminder: Collagen → connective tissue protein.

Q13. The most abundant protein in the biosphere is:
A) Hemoglobin
B) Collagen
C) Rubisco 
D) Keratin
Answer : C) Rubisco 
Reminder: Rubisco = enzyme of photosynthesis.

Q14. Phosphodiester bond is found in:
A) Proteins
B) Lipids
C) Nucleic acids 
D) Polysaccharides
Answer : C) Nucleic acids
Reminder: Phosphate + sugar linkage in DNA/RNA.

Q15. Which sugar is a ketose?
A) Glucose
B) Galactose
C) Fructose 
D) Ribose
Answer : C) Fructose
Reminder: Fructose = ketone sugar; glucose = aldehyde sugar.

Q16. Which lipid is amphipathic (polar + nonpolar ends)?
A) Triglyceride
B) Phospholipid 
C) Steroid
D) Wax
Answer : B) Phospholipid
Reminder: Phospholipids form bilayer in cell membrane.

Q17. The prosthetic group of hemoglobin is:
A) Globin
B) Iron
C) Heme 
D) Porphyrin
Answer : C) Heme
Reminder: Hemoglobin = Globin (protein) + Heme (Fe²⁺).

Q18. Sickle cell anemia is caused due to mutation in:
A) Collagen
B) Hemoglobin 
C) Myosin
D) Insulin
Answer : B) Hemoglobin
Reminder: Glutamic acid → Valine substitution in β-chain.

Q19. The bond between two nucleotides is:
A) Glycosidic
B) Phosphodiester 
C) Peptide
D) Hydrogen
Answer : B) Phosphodiester
Reminder: Nucleotides → linked by phosphodiester bonds.

Q20. Which biomolecule is amphoteric in nature?
A) Lipids
B) Proteins 
C) Carbohydrates
D) Nucleic acids
Answer : B) Proteins
Reminder: Amino acids act as acid (–COOH) & base (–NH₂).

Q21. Non-protein part of enzyme is called:
A) Cofactor 
B) Substrate
C) Prosthetic group
D) Apoenzyme
Answer : A) Cofactor
Reminder: Apoenzyme + Cofactor = Holoenzyme (active).

Review  The capsule

  •  Energy (mono, di, and poly) is equal to carbs.
  •  Lipids include hormones, membranes, and energy storage.
  •  DNA/RNA = nucleic acids -> genetic information.
  •  Proteins that catalyze reactions are called enzymes.

 Last-Minute NEET Tips

  •  Most frequently requested NEET questions:
  •  Storage of polysaccharides (glycogen versus starch).
  •  Proteins form peptide connections.
  •  DNA and RNA contain nitrogen bases.
  •  Biomolecules crossing across in chromatography.


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