Important Notes on Biomolecules for NEET Biology

An Outline of Some Essential Pointers in Biomolecules for NEET 

From plants to animals, every living organism is made up of tiny building blocks called cells. They are the smallest fundamental units making up our bodies and consist of several inorganic and organic compounds. Among these, all carbon-containing compounds which are found in living matter are known as biomolecules. 

Biomolecules are a very crucial part of the syllabus for NEET Biology. These extensive biomolecules notes will help you gain an edge over your competitors. 

Studying these biomolecules class 11 notes for NEET well in advance will go a long way into ensuring you get the best ranks in NEET 2020. 

Biomolecules – An Introduction

Organic compounds that make up the very backbone of a cell in living organisms are known as biomolecules. These could include a variety of compounds in varying proportions such as carbohydrates, fats and proteins. All of these biomolecules have vital functions to perform, and they are manufactured within the body.

While organic compounds may consist of straight-chain carbons, others can be cyclic rings, branched chains or combinations of any of these types. They have varying features, chemical properties and structures; this, in turn, leads to the difference in physical properties like boiling and melting points, solubility in water. Depending on their affinity towards water, biomolecules can be categorised further into hydrophilic and hydrophobic.

In the following biomolecules notes for NEET, you shall learn about the types of biomolecules, such as proteins as well as their structures.

Biomolecules: Types

As you proceed with these biomolecules notes, make sure you have a clear understanding of organic compounds and their properties. Doing so will help you understand the following points with clarity.

Biomolecules are Categorised into Four Types, Chiefly:

1. Carbohydrates

Carbohydrates are polysaccharides and are the final products of most of the metabolic processes in our body. They are the keystones of our metabolic machinery, and their molecular structure consists of numerous monosaccharides combined together. Most living cells are rich sources of carbohydrates, and it is safe to say that these biomolecules are the very genesis of life on our planet.

For instance, cellulose is a vital component of plant cells, and these are usually stored in the form of starch. Glucose, on the other hand, is the final metabolic product of photosynthesis, the process by which plants make food using sunlight. Saccharides are mainly of three types: monosaccharides, disaccharides and oligosaccharides. They are grouped based on the number of sugar molecules each of them contains.

Some typical sugars that we come across on a daily basis include sucrose, cellulose, fructose, glucose and dextrose.

Further, in these biomolecules class 12 notes, you’ll be introduced to the three basic types of carbohydrates containing sugar, namely, monosaccharides, oligosaccharides and disaccharides.

  1. Monosaccharides: They are the simplest carbohydrates and cannot be hydrolysed any further. They are present in the general chemical formulae of (CH2O)n. Examples of monosaccharides include ribose and glucose.

  2. Oligosaccharides: These are complex carbohydrates that yield two to ten subunits or monosaccharides. They are further divided into various categories. Examples include stachyose and raffinose.

  3. Disaccharides: Carbohydrates, that on hydrolysis yield two monosaccharide units, are known as disaccharides.  For instance, sucrose yields fructose and glucose. On the other hand, maltose yields two molecules of glucose on hydrolysis.

The following table covers all types of carbohydrates that are part of the biomolecules class 12 syllabus.


Monosaccharides and Derivatives



Monosaccharides, for example:


Number of monosaccharides ranging from 2-10.


Pentose – 5C

Heptose – 7C

Triose – 3C

Tetrose – 4C

  • Amino saccharides such as galactosamine

  • Glycosides such as nucleotides

  • Disaccharides

  • Tetrasaccharides

  • Trisaccharides

  • Homopolysaccharides such as starch and amylopectin

  • Heteropolysaccharides such as hyaluronic acid and heparin

2. Proteins

Organic compounds present in our diets in generous amounts and made of amino acids are called proteins. They consist of long-chain monomers bonded together with the help of polypeptide bonds. Therefore, proteins are also sometimes called polypeptides. 

What, then are amino acids?  Amino acids are carbon-containing organic compounds that consist of an amino group and a carboxylic acid group on each end. Each of these further comprise of a central carbon atom, bordered by four substituent radicals.

These radicals are mainly a hydrogen group, an amino group and a carboxylic acid group. A fourth group, usually depicted by R in chemical terms, is the variable group. Significantly, this variable group goes on to determine the type, nature and characteristics of the amino acid. Examples of amino acids are lysine, cysteine, glutamic acid and glycine. 

Let’s revise a few concepts from these biomolecules notes with the following MCQs.

Quick Recap

1) Which of these is not a carbohydrate?

a. Lactose.

b. Sucrose.

c. Lysine.

d. Dextrose.

2) Which of the following is a disaccharide?

a. Maltose.

b. Ribose.

c. Glucose.

d. Starch.

3. Lipids

These are a group of hydrophobic compounds that include fats, oils, steroids, phospholipids and glycerol. Depending on the types of constituents, lipids can vary in structure and properties. For instance, fatty acids are made up of a single carboxyl group bonded with a variable group or R. These fatty acids may be saturated or unsaturated.

Further, some lipids may comprise phosphorous groups bonded with the organic groups. They are also known as phospholipids. Phospholipids are the basic building block of the plasma membrane of cells.

4. Nucleic Acids

The smallest fundamental units of our genetic information, also called genes, consist of building blocks called DNA and RNA. These constitute the genetic material of our bodies and are a combination of nitrogenous bases, molecules of sugar and a phosphate group.

These may be heterocyclic such as purines and pyrimidines. Examples of purines are xanthine, caffeine and nitrogenous bases such as guanine and adenine. When nitrogenous bases form chemical binds with sugar molecules, the resulting product is called a nucleoside. These, in turn, combine with phosphate groups to result in nucleotides (RNA, DNA).

Secure a Spot in Top Medical Colleges with These Biomolecules Notes for NEET

Once you are done revising your basic biological concepts with the help of these biomolecules notes, make sure you test yourself with MCQs, short answer questions and sample test papers to prep yourself for the big day. Chalk out a streamline schedule and study routine, to help manage time effectively.

Make the most out of your preparatory months. With these biomolecules class 12 notes, you’ll be a step ahead in every exam and well-prepared to face the toughest questions in your NEET biology paper. 

FAQ (Frequently Asked Questions)

1. What are the Most Important Chapters for NEET in Biology?

Ans. Some crucial chapters in biology you need to focus on include Evolution, Biomolecules, Human Health and Disease, Biotechnology, etc.

2. What are Some Important Topics for NEET 2020?

Ans. Chapters you need to pay extra attention to include Diversity of Living Organisms, Human Physiology, Plant Physiology, Biomolecules, etc.

3. How Important is Biomolecules for NEET?

Ans. Biomolecules form one of the most crucial components of the biology syllabus for NEET. Make sure you have a clear understanding of all the topics covered in these biomolecules notes.