NCERT Class 11 Biotechnology Biotechnology: Chapter 3 — Biomolecules
This chapter, Biomolecules, introduces students to the essential organic molecules that form the basis of life. It details the four major types: carbohydrates, proteins, lipids, and nucleic acids, explaining their roles as structural components and functional entities within cells. The chapter begins by classifying carbohydrates into monosaccharides, oligosaccharides, and polysaccharides, providing examples like glucose and fructose. It elaborates on monosaccharides as simple sugars with aldehyde or ketone functional groups and a general formula of Cn(H2O)n. The text also touches upon the diverse functions of carbohydrates, including energy provision, storage, and their presence in cell walls and genetic material. This foundational knowledge is crucial for understanding cellular processes and the molecular basis of life in Biotechnology.
Quick info
| Board | CBSE / NCERT |
|---|---|
| Class | Class 11 |
| Subject | Biotechnology |
| Book | Biotechnology |
| Chapter | Chapter 3 — Biomolecules |
| Language | English |
| PDF type | NCERT Textbook |
| Session | CBSE 2026 |
| Reading time | 2 minutes |
| Word count | 364 |
Learning outcomes
- Identify the four major classes of biomolecules: carbohydrates, proteins, lipids, and nucleic acids.
- Understand the chemical nature and classification of carbohydrates (monosaccharides, oligosaccharides, polysaccharides).
- Recognize the diverse functions of carbohydrates in living organisms.
- Learn about the basic structure and formula of monosaccharides.
- Appreciate the role of biomolecules in cellular structure and processes.
Vocabulary
| Word | Meaning |
|---|---|
| Biomolecules | Organic molecules that form the basis of life, such as carbohydrates, proteins, lipids, and nucleic acids. |
| Macromolecules | Large biological molecules, often polymers, composed of many smaller subunits. |
| Carbohydrates | Organic compounds made of carbon, hydrogen, and oxygen, often serving as a primary energy source. |
| Lipids | A diverse group of organic compounds including fats, oils, and waxes, insoluble in water. |
| Proteins | Complex molecules made up of amino acids, essential for structure, function, and regulation of the body's tissues and organs. |
| Nucleic acids | Complex biomolecules, such as DNA and RNA, that carry genetic information. |
| Monosaccharides | Simple sugars that cannot be hydrolyzed into simpler forms; the basic unit of carbohydrates. |
| Oligosaccharides | Carbohydrates composed of a small number (2-10) of monosaccharide units. |
| Polysaccharides | Complex carbohydrates formed from long chains of monosaccharide units. |
| Aldehyde | An organic compound containing a functional group with the structure -CHO. |
| Ketone | An organic compound containing a functional group with the structure >C=O. |
| Glycosidic bond | A type of covalent bond that links a carbohydrate molecule to another group. |
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Practice questions
- What are the four major types of biomolecules discussed in this chapter? Answer: The four major types are carbohydrates, proteins, lipids, and nucleic acids.
- What is the general formula for monosaccharides? Answer: The general formula for monosaccharides is Cn(H2O)n.
- Name the three categories of carbohydrates based on their structure. Answer: The three categories are monosaccharides, oligosaccharides, and polysaccharides.
- What is the primary role of carbohydrates in living organisms? Answer: The primary role of carbohydrates is to function as a primary source of energy.
- Give examples of disaccharides mentioned in the text. Answer: Examples of disaccharides mentioned are maltose, lactose, and sucrose.
Frequently asked questions
What are biomolecules and why are they important?
Biomolecules are organic molecules essential for life, forming cellular structures and carrying out vital functions. They include carbohydrates, proteins, lipids, and nucleic acids.
How are carbohydrates classified?
Carbohydrates are classified into three main categories: monosaccharides (simple sugars), oligosaccharides (short chains of sugars), and polysaccharides (complex sugars).
What is a monosaccharide?
A monosaccharide is the simplest form of sugar, which cannot be broken down further by hydrolysis. Examples include glucose and fructose.
What is the general chemical formula for monosaccharides?
The general chemical formula for monosaccharides is Cn(H2O)n.
What are some functions of carbohydrates in living organisms?
Carbohydrates serve as a primary source of energy, energy stores, metabolic intermediates, and are components of cell walls, DNA, and RNA.
What are oligosaccharides?
Oligosaccharides are carbohydrates made up of two to ten monosaccharide units linked together by glycosidic bonds. Disaccharides like sucrose are common examples.
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NCERT Class 11 Biotechnology — Biotechnology — Chapter 3 — Biomolecules. Verified by NCERT Help Editorial Team. Reviewed on 29 Jul 2026. Last updated 10 Aug 2026.