---
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entity_type: "chapter"
id: "66def8c03f8b4e9e69bdb50b"
title: "Biomolecules"
board: "CBSE"
curriculum: "CBSE"
class: "Class 12"
subject: "Chemistry"
book: "Chemistry - II"
chapter: "Biomolecules"
chapter_slug: "biomolecules"
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source: "Edzy"
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last_updated: "2026-06-20"
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# Biomolecules

A living system grows, sustains, and reproduces itself, composed of non-living atoms and molecules. The study of chemical processes within living systems is termed biochemistry. Various complex biomolecules such as carbohydrates, proteins, nucleic acids, and lipids make up living systems, with some simple molecules like vitamins and mineral salts playing crucial roles.

## Knowledge Snapshot

| Field | Details |
| :--- | :--- |
| Class | Class 12 |
| Subject | Chemistry |
| Book | Chemistry - II |
| Chapter | Biomolecules |
| Pages | 281-302 |

## Chapter Summary

### Short Summary
This chapter covers the structures and functions of essential biomolecules like carbohydrates, proteins, nucleic acids, and hormones, discussing their importance in biological systems.

### Detailed Summary
The chapter introduces biomolecules, explaining their essential roles in living systems. It emphasizes the significance of carbohydrates, proteins, nucleic acids, and other biomolecules in nutritional and cellular functions. The classification of carbohydrates into monosaccharides, oligosaccharides, and polysaccharides is detailed, along with functional group characteristics, aiding in the understanding of biochemistry and cellular processes.

## Topic-Wise Explanation

### Carbohydrates
Carbohydrates are primarily formed by plants and consist of compounds like cane sugar, glucose, and starch, typically represented by the formula Cx(H2O)y. They are classified into monosaccharides, oligosaccharides, and polysaccharides based on hydrolysis behavior. Monosaccharides are simple sugars, oligosaccharides yield 2 to 10 units, and polysaccharides yield numerous monosaccharide units. Reducing sugars are identified by their reactions with Fehling’s and Tollens’ reagents.

### Proteins
[Omission: Not covered in the provided context.]

### Enzymes
[Omission: Not covered in the provided context.]

### Vitamins
[Omission: Not covered in the provided context.]

### Nucleic Acids
[Omission: Not covered in the provided context.]

### Hormones
[Omission: Not covered in the provided context.]

## Core Ideas

| Idea | Explanation |
| :--- | :--- |
| Biomolecules | Molecules crucial for sustaining life, including carbohydrates, proteins, and nucleic acids. |

## Key Concepts

| Concept | Meaning |
| :--- | :--- |
| Monosaccharide | The simplest form of carbohydrates that cannot be hydrolyzed. |
| Oligosaccharides | Carbohydrates that yield 2-10 monosaccharides on hydrolysis. |
| Polysaccharides | Carbohydrates yielding many monosaccharide units on hydrolysis. |
| Reducing sugars | Sugars that can reduce certain chemical reagents. |

## Important Points for Revision
* Living systems consist of non-living molecules.
* Biochemistry studies the chemical processes in living systems.
* Carbohydrates are classified based on hydrolysis.
* Monosaccharides are the simplest carbohydrates.
* Oligosaccharides comprise 2-10 monosaccharide units.
* Polysaccharides yield many monosaccharides upon hydrolysis.
* Reducing sugars reduce Fehling's and Tollens' solutions.
* Functional groups play significant roles in biomolecule characteristics.

## Vocabulary and Glossary

| Word / Phrase | Meaning |
| :--- | :--- |
| Saccharides | Another term for carbohydrates, derived from Greek meaning sugar. |
| Aldose | A type of monosaccharide with an aldehyde group. |
| Ketose | A type of monosaccharide with a keto group. |

## Practice Questions

### Short Answer Questions
1. What are the different types of carbohydrates?
2. How do reducing sugars act in chemical solutions?
3. Define monosaccharides.
4. What is the general formula of carbohydrates?
5. Give examples of polysaccharides.

### Long Answer Questions
1. Explain the classification of carbohydrates based on hydrolysis.
2. Discuss the chemical characteristics of carbohydrates as biomolecules.
3. Compare and contrast monosaccharides and polysaccharides in terms of structure and function.

## Related Concepts
[Omission: None provided in the context.]

## Source Attribution

| Field | Value |
| :--- | :--- |
| Source | Edzy |
| Reference Type | examSubjectBookChapter |
| Reference ID | 66def8c03f8b4e9e69bdb50b |
| Canonical URL | https://www.edzy.ai/cbse-class-12-chemistry-chemistry-ii-biomolecules |
| Markdown URL | https://www.edzy.ai/okf/chapter/cbse-class-12-chemistry-chemistry-ii-biomolecules.md |