Biomolecules: Chemical Composition Analysis

Things around us have been classified as living and non-living things depending on whether the cell constitutes the matter or not. All living organisms are made up of a fundamental unit called the cell. However, if we further divide a cell, we can see that it is made up of atoms. The cell consists of organic and inorganic compounds. Thus, on the basis of the chemical analysis, we can conclude that everything in this world is made up of same chemicals. They differ only in their proportion. Let’s take a glance at chemical composition called biomolecules in living organisms.

Analysis of Chemical Composition

The elemental analysis of a cell shows that it is made up of various elements such as carbon, hydrogen, oxygen, chlorine, etc. But what do these elements constitute? What are the properties of the compounds formed by these elements? Only a chemical analysis can answer these questions. Analytical techniques provide information regarding different compounds (organic and inorganic), their molecular formula and structures. They also help us to isolate and purify one compound from another.

Take a piece of living tissue and crush and mix it with an acid. After its filtration, we obtain two portions. The fraction which is obtained as filtrate is acid-soluble portion while the other fraction is acid-insoluble, which retain on the filter membrane. This shows that within the tissues, there two or more compounds which have distinct properties.

Take another piece of tissue and burn it, once all water in it is evaporated. All carbon compounds will be oxidized on burning. The left out ash gives us the inorganic compounds like calcium, magnesium, sulfate, phosphate, etc., in the tissue.

Analysis of Chemical Composition- Biomolecules


All carbon-containing compounds (organic compounds) found in the living organisms are termed as biomolecules. They are organic molecules present in a living cell which include carbohydrates, proteins, fats, etc. Every biomolecule is essential for the body functions and is manufactured by the body. It can vary in nature, type, and structure. Some are straight chains; others may be cyclic rings or both. Moreover, they can vary in their physical properties such water solubility and melting points. Biomolecules are made up of functional groups. In a cell, the functional groups of biomolecules are as follows:

Amino acids

Amino acids are carbon-containing compounds where a carboxylic acid group and the amino group are present at the two ends. Each amino acid consists of one central carbon surrounded by four substituents. These four substituents include an amino group, carboxylic acid group, hydrogen and a variable group represented by R. The variable group, R decides the nature and type of amino acid.


Lipids are a group of water-insoluble compounds which includes fats, glycerol, phospholipids, steroids, oils, etc. Types of lipids vary according to their constituents. Fatty acids are simple lipids, made up of carboxyl group and a variable group, R. They may be saturated or unsaturated fatty acids. Glycerols are trihydroxy propane which combines with fatty acids to give triglycerides. Some lipids consist of a phosphorus group along with the organic chain. Such lipids are called phospholipids which are the constituent of the plasma membrane.

Nucleic acids

Nucleic acids are the genetic materials present in an organism, which include DNA and RNA. They are the combination materials of nitrogenous bases, sugar molecules and phosphate group linked by different bonds in a series of steps. Our body consists of heterocyclic compounds like pyrimidines and purines. These are nitrogenous compounds like adenine, guanine, cytosine thymine and uracil. When these bases bond with sugar chains, they form nucleosides. Nucleosides, in turn, bond with the phosphate group to give nucleotides like DNA and RNA.

Stay tuned with Byju’s to learn more about biomolecules and their functions.

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