Biomolecules: Chemical Composition Analysis

What are Biomolecules?

Biomolecules are organic macromolecules that play roles in the living organisms’ existence. These are carbohydrates; proteins; lipids and nucleic acids. Biomolecules are involved in virtually all the structures and activities that occur in cells since they are the fundamental units of life. The knowledge of biomolecules is essential in biology as they are involved in all cellular biochemical activities ranging from energy production to DNA synthesis and transmission.

Latest: NEET 2024 Paper Analysis and Answer Key 

Don't Miss: Most scoring concepts for NEET | NEET papers with solutions

New: NEET Syllabus 2025 for Physics, Chemistry, Biology

NEET Important PYQ & Solutions: Physics | Chemistry | Biology

Types of Biomolecules

The various types of biomolecules are:

Carbohydrates

Definition and General Structure: Carbohydrates are organic molecules composed of carbon, hydrogen, and oxygen, usually in a 1:In terms of the crisis communicators, the preferred ratio in this aspect is 2:1. They can be and often are simple sugars, but can also be complex polysaccharides.

Types: Monosaccharides, Disaccharides, Polysaccharides: For example, glucose is a kind of simple sugar and is also classified as a monosaccharide. The oligosaccharides; contain more than two monosaccharides but less than a polysaccharide like a sucrase. Starch and cellulose are examples of polysaccharides because they are large structures made up of monosaccharide components.

Functions in the Body: Besides being a source of energy, carbohydrates are essential in the structure of cells and cell signaling.

Examples: Some of the examples of carbohydrates include glucose, a monosaccharide; starch, a polysaccharide that acts as an energy store in plants; cellulose another polysaccharide found in the cell walls of plants as a structural component.

Proteins

Definition and General Structure: Proteins can be described as large biomolecules that are created from amino acids that are joined by peptide bonds to form structures with great complexity and intricacy regarding their shape.

Amino Acids: Building Blocks of Proteins: Protein is also known as an amino acid polymer because it is made up of organic compounds which are amino acids, and 20 different types of amino acids play a role in the protein variant.

Levels of Protein Structure: Primary, Secondary, Tertiary, Quaternary: Protein structure has four levels: firstly, the primary structure consists of amino acid sequences, secondly, secondary structures are formed by alpha helices and beta sheets, thirdly, the tertiary structure by the 3D folding, and finally the quaternary one is a set of multiple polypeptide chains.

Functions: Protein is involved in enzymatic activities, as hormones, in the structure and shape of the cells, and acts in immune defence too.

Examples: Some of them include; Hemoglobin in the transportation of oxygen, Keratin, a structural protein present in hair and nails, and insulin a hormone that helps regulate blood sugar.

Lipids

Definition and General Structure: Lipids include compounds soluble in nonpolar solvents they contain a large number of carbon-hydrogen atoms in long chains or the form of rings.

Types: Triglycerides act as energy storage or fat, phospholipids are part of cell membranes and steroids encompass cholesterol which is a hormone.

Functions: Lipids are involved in energy storage, and the determination of membrane fluidity plays a role in signal transduction.

Examples: Usual lipids are the fats and oils (triglycerides), phospholipids that set up cell membranes, and sterol–cholesterol.

Nucleic Acids

Definition and General Structure: Nucleic acids can be defined as large biomolecules that are made up of a chain of nucleotides; a nucleotide is a molecule that has both a sugar as well as a phosphate group and contains a nitrogenous base.

Types: DNA and RNA: Deoxyribonucleic acid or DNA is an example of a genetic molecule that contains information and ribonucleic acid or RNA is responsible for the expression of the stored information.

Functions: Nucleic acids are involved in the replication of genetic data and also involved in the synthesis of proteins and transmission of heredity.

Examples: DNA and RNA where DNA is the carrier of the code and RNA takes a part in the code implementation.

Analysis of chemical composition

The chemical composition is discussed below:

Basic Elements in Biomolecules

Carbon: Carbon is among the most critical elements in biomolecules mainly because it is the basis for organic molecules. It is capable of forming 4 covalent bonds.

Hydrogen: Hydrogen atoms are engaged in the creation of stable compounds with carbon and oxygen. They are a structural part of water and organic molecules.

Oxygen: Oxygen helps in the process of cellular respiration and is part of the composition of water and many organic compounds which makes them more reactive.

Nitrogen: Nitrogen is a very important component of amino acids, nucleotides, and other biomolecules that form proteins and nucleic acids.

Phosphorus: Phosphorus is necessary for the development of nucleotides – the DNA and RNA building blocks, and also as part of ATP, through which cells receive energy.

Sulfur: In some of the amino acids and vitamins, sulfur takes an important position regarding protein conformations as well as enzymes.

Types of Bonds in Biomolecules

Covalent Bonds: Covalent bonds interlock two atoms by sharing two electrons or electron pairs and form the basics of the structure of biomolecules.

Ionic Bonds: In ionic bonds, there is static charge attraction between the two particles and this plays an important role in the structure and properties of compounds such as salts.

Hydrogen Bonds: It is a weak intermolecular force that takes place between polar molecules. It is essential in the properties of water and the stability of DNA and proteins.

Van der Waals Forces: Van der Waals forces are the weak forces that exist between molecules because of the varying charges on the molecules; they are crucial in the formation of the shape, as well as the working of large biomolecules.

Carbohydrates: Detailed Analysis

The simplest carbohydrates are the monosaccharides, which are sugars that are made of one monomer; they include glucose. A disaccharide is a compound that is formed when two monosaccharides join together for instance sucrose and lactose. These are large carbohydrate compounds that are characterized by long chains of monosaccharide units; examples of polysaccharides include; starch, glycogen, and cellulose.

Chemical Tests for Carbohydrates: This test determines reducing sugars. The presence of reducing sugars can be deduced from a change of color from blue, green, and yellow to red when a carbohydrate solution is heated with Benedict’s reagent.

Examples and Functions in the Human Body: Glucose on its side is used as the major source of energy for the cells. Glycogen is used as the main stored energy in the form of liver and muscle glycogen deposits. In cell walls of plant cells, cellulose contributes to the structural role since it is rigid, while, in the human diet, fiber which consists of different polysaccharides assists in digestion.

Diagram: Structure of Glucose

Proteins: Detailed Analysis

Amino Acids and Peptide Bonds: Protein is compositionally made from amino acids, this is polymerized through elimination synthesis or dehydration synthesis. The individual building block of each protein is called an amino acid and it has an amino group, a carboxyl group, and an amino acidspecific side chain or branch (R group).

Levels of Protein Structure

Primary: The specific linear array of amino groups into a polypeptide chain.

Secondary: The secondary structure of the polypeptide chain in which the segments of the chain may coil into αhelices and βpleated sheets.

Tertiary: The gross conformation of a single polypeptide chain in which the polypeptide backbone is maintained in threa edimensional shape through interactions of the side chains.

Quaternary: A condition in which many polypeptide subunits make up a protein complex.

Functions of Proteins in the Human Body

There are numerous roles that proteins have to play and some of the most common ones include; enzymes, structure, transport, signal, and immunity.

Chemical Tests for Proteins (Biuret Test)

The Biuret test works by using a Biuret reagent that when reacts with proteins produces a violet coloration and this is due to the presence of peptide bonds.

Diagram: Structure of an Amino Acid

Lipids: Detailed Analysis

The analysis is discussed below:

Types of Lipids

Fats: Semisolid at room temperature and including mainly saturated fatty acids in fats.

Oils: At congealed state, oily liquid with no solid particles at room temperature and predominantly contains unsaturated fatty acids.

Phospholipids: Glycerol, two fatty acids, and phosphate groups that directly compose membranes, and are principal parts of the lipids layer.

Steroids: Derivatives of fatty acids with several rings, for example, cholesterol and steroid hormones, testosterone, and estrogen.

Functions of Lipids in the Human Body

Lipids function as the energy reserve molecules, parts of cell membranes, signaling agents, and the protectant layer.

Chemical Tests for Lipids

During the emulsion test, lipids form a cloudy white solution when ethanol and water are added to the mixture.

Nucleic Acids: Detailed Analysis

The analysis is discussed below:

Structure and Function

DNA is a double helix and contains the information for making proteins and RNA, which is a single chain and assists in protein synthesis and gene control.

Nucleotides

Nucleotides are molecules that are made up of a sugar a phosphate group and a nitrogenous base. Nucleotides are a combination of a phosphate group, a sugar, and a nitrogenous base. They connect each other which forms the structure of DNA and RNA nucleotides.

Functions

The genetic information within DNA is expressed as genetic code within its sequence of bases; this code is then transcribed into RNA. DNA communicates this information to RNA and it in turn converts these instructions into proteins, which perform cellular operations.

Diagram: Structure of DNA Double Helix

Methods of Chemical Composition Analysis

The methods are discussed below:

Chromatography

This technique relies on the principle of differential migration of the components of the mixture on a stationary phase. There’s no doubt, that it is used to help detect and estimate the amounts of specific compounds in multicomponent systems.

Spectroscopy

Spectroscopy is a field of study that has to do with the use of light to interact with matter to analyze the makeup of a given substance. Molecular spectroscopy such as UVVis, IR, and NMR are widely used and valuable methods in chemical analysis.

Electrophoresis

This technique employs an electric field to separate molecules according to their size and or electrical charge. Much utilized in the examination of nucleic acids as well as proteins.

Xray Crystallography

It is a technique for finding out the atomic and molecular constitution of a crystal by analyzing the diffraction of Xrays. It is important when it comes to establishing the finer forms of biomolecules.

Use of Enzymes in Analysis

Enzymes are applied as selective reagents in detecting or measuring substances in biochemical analysis. They are widely used in diagnosis and biochemical activities.

Applications of Biomolecule Analysis

The applications are discussed below:

Medical Diagnostics

Bioanalysis of biomolecules has a critical role in the diagnosis of diseases. The prognosis of health status and the creation of molecular medicine are based on biomarkers.

Forensic Science

Analyzing biomolecules including DNA and proteins, assists in cases of human identification including criminals, forensic cases, and identification of family relationships besides identifying unknown individuals.

Biotechnological Applications

Biotechnology involves the evaluation of biomolecules in genetic manipulation, pharmaceutical processes, and the production of industrial enzymes that improve other related sciences.

Agricultural Improvements

Knowledge of biomolecules contributes to creating GM crops, improving plants' immunity to pests and diseases and increasing the nutritional table.

Recommended for Biomolecules: Chemical Composition Analysis