---
type: "Chapter"
knowledge_type: "chapter"
entity_type: "chapter"
id: "66f145af0821118bf5c5e414"
title: "Biomolecules"
board: "CBSE"
curriculum: "CBSE"
class: "Class 11"
subject: "Biology"
book: "Biology"
chapter: "Biomolecules"
chapter_slug: "biomolecules"
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source: "Edzy"
version: 1
last_updated: "2026-06-20"
---

# Biomolecules

This chapter explores the diversity of living organisms and the chemical components that constitute them, identifying both organic compounds known as biomolecules and the inorganic constituents present in living tissues.

---

## Knowledge Snapshot

| Field | Details |
| :--- | :--- |
| Class | Class 11 |
| Subject | Biology |
| Book | Biology |
| Chapter | Biomolecules |
| Pages | 104-119 |

---

## Chapter Summary

### Short Summary
This chapter discusses the chemical composition of living organisms, detailing how various organic compounds, termed biomolecules, are analyzed and classified, along with the presence of inorganic materials.

### Detailed Summary
The chapter begins by presenting the elemental analysis of living tissues compared to non-living matter, highlighting that both share similar elements but differ in the abundance of carbon and hydrogen in living organisms. It describes chemical analysis performed on living tissues to uncover organic compounds, separating them into an acid-soluble pool and an acid-insoluble fraction. Various organic compounds, collectively referred to as biomolecules, are identified through this analysis. The chapter classifies biomolecules into amino acids, nucleotides, and fatty acids, discussing their structures, properties, and functions in biological processes. Amino acids, for instance, are identified as α-amino acids, while lipids are categorized based on saturation levels as fats or oils. Details about the formation of complex lipid structures, such as phospholipids in cell membranes, are also included.

---

## Topic-Wise Explanation

### How to Analyse Chemical Composition?
The chemical composition of living tissues is analyzed through elemental analysis, comparing the results of plant and animal tissues to that of non-living matter. This involves grinding the tissue in trichloroacetic acid and separating the resulting slurry into two fractions.

### Primary and Secondary Metabolites
The chapter discusses the classification of biomolecules based on their role and formation, although specific details on primary and secondary metabolites may be inferred but are not explicitly mentioned in the text.

### Biomacromolecules
The chapter indirectly references macromolecules through the discussion of amino acids and lipids, which are building blocks of larger biological molecules, although further details on specific macromolecules are not provided.

### Proteins
Proteins are composed of amino acids, which are identified and characterized based on their R groups. There are twenty specific types of amino acids that form proteins.

### Polysaccharides
While polysaccharides are part of the discussion on biomolecules, the chapter does not provide a detailed analysis or specific examples of them.

### Nucleic Acids
Nucleic acids are mentioned as a class of biomolecules, although details specific to their structures or functions are not given.

### Structure of Proteins
Proteins' structures are discussed in relation to their amino acid composition, specifically focusing on the properties of different functional groups within amino acids.

### Enzymes
Enzymes are implied through the discussion of proteins and their functions in biological processes, but specific information regarding enzyme structure or function is not covered.

---

## Core Ideas

| Idea | Explanation |
| :--- | :--- |
| Composition of Biomolecules | Living organisms consist of biomolecules, which are primarily carbon-based compounds identified through chemical analysis. |

---

## Key Concepts

| Concept | Meaning |
| :--- | :--- |
| Amino Acids | Organic compounds that serve as the building blocks of proteins, containing an amino group and a carboxyl group. |
| Fatty Acids | Building blocks of lipids, characterized by a long hydrocarbon chain and a carboxyl group. |

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## Important Points for Revision

* Living organisms share elemental constituents with non-living matter.
* Elemental analysis of living tissues reveals higher carbon and hydrogen proportions.
* Chemical analysis of tissues separates organic compounds into distinct fractions.
* Biomolecules include amino acids, fatty acids, and other organic compounds.
* Amino acids are classified based on their R groups into various categories.
* Lipids can be saturated or unsaturated and include substances like triglycerides.
* Phospholipids play a key role in the structure of cell membranes.
* The functions of biomolecules are integral to biological processes and structures.
* Analytical techniques are used to deduce the molecular formula and structure of biomolecules.

---

## Vocabulary and Glossary

| Word / Phrase | Meaning |
| :--- | :--- |
| Filtrate | The liquid that passes through a filter in the separation process. |
| Retentate | The solid that remains on the filter after filtration. |

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## Practice Questions

### Short Answer Questions
1. What two fractions are obtained from grinding living tissue in trichloroacetic acid?
2. How are amino acids classified based on their structure?
3. What distinguishes saturated from unsaturated fatty acids?
4. What is the composition of ash remaining after burning living tissue?
5. Can you name any examples of essential amino acids?

### Long Answer Questions
1. Describe the process of separating organic compounds from living tissues and the significance of this process.
2. Discuss the classification of amino acids and provide examples of different types.
3. Explain the structure and function of lipids in biological systems.
4. How do the inorganic constituents present in living tissues compare to those found in non-living matter?

---

## Related Concepts

* Organic Compounds
* Inorganic Compounds
* Functional Groups
* Cell Membrane

---

## Source Attribution

| Field | Value |
| :--- | :--- |
| Source | Edzy |
| Reference Type | examSubjectBookChapter |
| Reference ID | 66f145af0821118bf5c5e414 |
| Canonical URL | https://www.edzy.ai/cbse-class-11-biology-biomolecules |
| Markdown URL | https://www.edzy.ai/okf/chapter/cbse-class-11-biology-biomolecules.md |