Important Questions Class 12 Chemistry Chapter 10

Chapter 10 of Class 12 Chemistry focuses on Biomolecules, which are essential compounds in living organisms. This chapter is important for the Class 12 board exam, which held on 28 February 2026, as questions from carbohydrates, proteins, vitamins, and enzymes often appear in both short and long answer sections.

Understanding these concepts helps students score well, as the chapter tests knowledge of definitions, structures, functions, and reactions of biomolecules. Here, we have compiled a list of Important Questions Class 12 Chemistry Chapter 10 to help students revise effectively. These questions include short answers, definitions, and multiple-choice questions.

Important Questions Class 12 Chemistry Chapter 10

Biomolecules are the building blocks of life and play a vital role in the structure and functioning of all living organisms.

A clear understanding of this chapter is essential, not just for exams but also for grasping basic biological chemistry concepts. The questions in this chapter are frequently asked in the Class 12 board exam, making it important for students to revise them thoroughly.

1. Which of the following is a polysaccharide?
   (1) Maltose
   (2) Sucrose
   (3) Fructose
   (4) Cellulose
   Answer: Cellulose
   Explanation: Polysaccharides are long chains of monosaccharide units. Maltose and sucrose are disaccharides, while fructose is a monosaccharide. Cellulose is made of many glucose units linked together, making it a polysaccharide.

2. Define essential and non–essential amino acids.
   Answer:

• Essential amino acids cannot be synthesized by the body and must be obtained from food.

• Non-essential amino acids can be synthesized by the body.
  Explanation: Amino acids are the building blocks of proteins. The body requires some amino acids from diet (essential), while others can be produced internally (non-essential).

3. Name a water-soluble vitamin and the disease caused by its deficiency.
   Answer: Vitamin C; Disease: Scurvy
   Explanation: Water-soluble vitamins dissolve in water and are not stored in the body for long. Lack of Vitamin C leads to scurvy, which causes bleeding gums and weakness.

4. Write any two differences between DNA and RNA.
   Answer:

• DNA contains deoxyribose sugar; RNA contains ribose sugar.

• DNA is double-stranded; RNA is single-stranded.
  Explanation: DNA stores genetic information and remains stable in cells, whereas RNA helps in protein synthesis and is more reactive.

5. The carbohydrate stored in liver, muscles, and brain of animals is ______.
   Answer: Glycogen
   Explanation: Glycogen acts as an energy reserve in animals. It can be quickly broken down into glucose when the body needs energy.

6. Which monosaccharide will be obtained by the hydrolysis of maltose?
   a) Glucose
   b) Fructose
   c) Lactose
   Answer: Glucose
   Explanation: Maltose is a disaccharide made of two glucose units. Hydrolysis breaks it down into glucose molecules.

7. What are enzymes?
   Answer: Enzymes are biological catalysts that speed up chemical reactions without being consumed.
   Explanation: Enzymes reduce the activation energy of reactions and are specific for their substrates. They are crucial in all biochemical processes.

8. Name the disease caused by deficiency of vitamin A.
   Answer: Night blindness
   Explanation: Vitamin A is necessary for the formation of retinal pigments in the eye. Its deficiency impairs vision in low light conditions.

9. Explain the denaturation of protein.
   Answer: Denaturation is the process in which proteins lose their natural structure due to heat, pH changes, or chemicals, affecting their function.
   Explanation: The 3D structure of a protein determines its function. Denaturation unfolds the protein, making it inactive, but does not break peptide bonds.

10. Name the linkage between two monosaccharide units in a disaccharide.
    Answer: Glycosidic linkage
    Explanation: Monosaccharides join through a covalent bond called glycosidic linkage, formed between a hydroxyl group of one sugar and the anomeric carbon of another.

11. Which vitamin is responsible for blood clotting?
    Answer: Vitamin K
    Explanation: Vitamin K is required for the synthesis of prothrombin, a protein essential for blood clotting.

12. α–D–(+) glucose and β–D–(+) glucose are:
    (1) Metamers
    (2) Anomers
    (3) Geometrical isomers
    (4) Functional group isomers
    Answer: Anomers
    Explanation: Anomers are isomers that differ only in the configuration around the anomeric carbon (C1) of glucose.

13. Match the following:

Explanation: Each compound has a specific role. Vitamins prevent deficiency diseases, starch is a storage polysaccharide, aldoses like glucose provide energy, enzymes catalyze reactions, and fructose is a simple sugar used for energy.

These Important Questions Class 12 Chemistry Chapter 10 cover all key areas of Biomolecules. Practicing them alongside Biomolecules class 12 important questions, Biomolecules class 12 chemistry important question, and class 12 chemistry Biomolecules mcq helps students strengthen concepts and revise efficiently for exams.