Biomolecules

What are Biomolecules?

Biomolecules are organic compounds found in the human body, playing a major role in both structure and function. The types of biomolecules include proteins, carbohydrates, lipids, nucleic acids, vitamins, and minerals. Carbohydrates and lipids are available for energy production and storage, while nucleic acids such as DNA and RNA carry genetic information. Biomolecules are also important for enzyme activity, cell signalling, transport, and communication throughout the body.

Types of Biomolecules

Biomolecules are needed by the body to perform different life processes. The various types of biomolecules are listed below:

Carbohydrates – Structure and Functions

Carbohydrates are organic molecules composed of carbon, hydrogen, and oxygen. Usually, the preferred ratio in this aspect is 2:1. They can be and often are simple sugars, but can also be complex polysaccharides. Sugar and starch are basic forms of carbohydrates. They are responsible for providing energy and also help in building the cell walls of the cell. Carbohydrates can be simple, like glucose or complex, like starch.

Types of Carbohydrates

Different types of carbohydrates are discussed below:

Functions of Carbohydrates

Some of the major functions of carbohydrates are discussed below in the table:

Examples of Carbohydrates

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

Proteins – Types and Roles

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. Proteins are made up of amino acids, and they are responsible for functions like building body structure and speeding up the reactions taking place in different processes.

They work as catalysts and are responsible for determining the shape of how they work. Sometimes they also work as enzymes. 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.

Types of Proteins

Some major types of protein and their structure and composition are discussed below:

Functions of Protein

Protein is involved in enzymatic activities, as hormones, in the structure and shape of the cells, and acts in immune defence too. Some major functions are discussed below in the table:

Examples of Protein

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

Lipids – Structure and Classification

Lipids include compounds soluble in nonpolar solvents, they contain a large number of carbon-hydrogen atoms in long chains or the form of rings. Lipids are responsible for storing fats and oils. It is also important because it is a form of storage of energy, and it also forms the cell membrane of the cell. Lipids are also important for processes like sending signals from one cell to another. They are generally insoluble and can be both saturated and unsaturated fats.

Types of Lipids

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

Functions of Lipids

Lipids are involved in energy storage, determination of membrane fluidity plays a role in signal transduction. Some of the major functions of lipids are discussed below:

Examples of Lipids

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

Nucleic Acids – DNA, RNA, and Nucleotides

Nucleic acids can be defined as large biomolecules that are made up of a chain of nucleotides. A nucleotide is a molecule that has a sugar, a phosphate group and a nitrogenous base. Nucleic acids are responsible for storing genetic information. DNA and RNA are made up of nucleotides and are two of the best compounds to carry genetic information. DNA carries long-term genetic data, while RNA helps the formation of different types of protein in the body.

Types of Nucleic Acids

Major types of nucleic acids are discussed below in the table:

Functions of Nucleic Acids

Nucleic acids are involved in the replication of genetic data and also in the synthesis of proteins, and the transmission of heredity. Some major ones are discussed below in the table:

Examples of Nucleic Acids

DNA and RNA, where DNA is the carrier of the code and RNA takes part in the code implementation.

Vitamins and Coenzymes

Some of the small organic molecules that help the enzymes to do their job in the chemical reactions are known as coenzymes. These are responsible for the overall metabolic speed and the metabolism of our body.

Types of Vitamins and Coenzymes

Some of the major types of vitamins and coenzymes are discussed below:

Functions of Vitamins and Coenzymes

Some of the major functions of vitamins and coenzymes are discussed below in the table:

Examples of Vitamins and Coenzymes

Examples of Vitamins: Vitamin A (retinol), Vitamin C (ascorbic acid), Vitamin D, Vitamin E, Vitamin K, and B-complex vitamins such as B₁ (thiamine), B₂ (riboflavin), B₃ (niacin).

Examples of Coenzymes: NAD⁺ (derived from niacin), FAD (derived from riboflavin), Coenzyme A (derived from pantothenic acid), and TPP (derived from thiamine).

Functions of Biomolecules

Some important functions of Biomolecules are discussed below:

Synthesis and Breakdown of Biomolecules

The synthesis and breakdown of biomolecules includes following pathways:

Anabolic Pathways

In anabolism, small and simpler molecules are converted into large and complex molecules, requiring energy input.

Examples include amino acids form keratin, glucose molecules forms glycogen and starch

Catabolic Pathways

In catabolism, large complex molecules are degraded into smaller simpler molecules.

Examples include protein is broken down into amino acids, lipids are broken into fatty acids

These two pathways are essential for total metabolism in an organism. The difference between the two is given in the table below:

Enzymatic Reactions

Catalytic actions of enzymes are involved in biosynthesis as well as the degradation of biomolecules. As such, enzymes facilitate metabolic reaction processes by increasing the rate of such processes.

For example, the specific enzymes DNA polymerase are used to synthesise DNA and proteases are used to deconstruct proteins into amino acids.

Metabolic Pathways Examples

Major examples of Metabolic Pathways are discussed below in the table:

Role of Biomolecules in Health

Biomolecules play an important role in maintaining human health:

Importance in Metabolism and Homeostasis

Biomolecules are involved in the regulation of physiological processes leading to a complex organism’s homeostasis and health condition. They include carbohydrates that supply energy, proteins required for tissue building and enzymatic processes, lipids that are useful in the formation of cell membranes and for energy storage, and nucleic acids that contain stored hereditary material.

Disorders Related to Biomolecule Metabolism

Some common disorders related to biomolecule metabolism are:

Biomolecules as Therapeutic Targets

Biomolecules play a central role in the process of finding therapeutic approaches. Strategies that aim at particular biomolecules alter diseases; for example, insulin among diabetic patients, statins in minimising cholesterol, and enzyme replacement therapy in cases of PKU. As the fields of biotechnology and pharmacology keep developing, biomolecular aims and objectives remain utilised and implemented in novel therapies and patient’ benefits.

Biomolecules NEET MCQs (With Answers & Explanations)

Important topics in the chapter Biomolecules are the

• Types of Biomolecules (Proteins, Carbohydrates, Lipids, Nucleic Acids)

• Functions of Biomolecules

• Biomolecules in Health and Diseases

• Enzymes

Practice Questions for NEET

Q1. The cellular pool comprises hundreds of organic and inorganic biomolecules. The organic molecules include

1. Carbohydrates

2. Proteins

3. Nucleic acids

4. More than one option correct

Correct answer: 4) More than one option correct

Explanation:

The organic molecules present within the cell are categorized into:

1. Carbohydrates:
- Monosaccharides (e.g., glucose) are simple sugars serving as energy sources.
- Polysaccharides (e.g., starch, glycogen) are complex carbohydrates providing both energy and structural support to cells.

2. Proteins:
- Composed of amino acids, proteins are fundamental to various cellular activities such as enzyme function, structural integrity, signal transmission, and material transport.

3. Lipids:
- This group encompasses fats, phospholipids, and steroids which are crucial for energy storage, maintaining cell membrane structure, and participating in signaling pathways.

4. Nucleic Acids:
- DNA and RNA are the genetic material, essential for storing, transferring, and synthesizing proteins according to genetic instructions.

Hence, the correct answer is option 4) More than one option is correct.

Q2. Organic molecules contain

1. Nitrogen

2. Sulphur

3. Oxygen

4. Zinc

Correct answer: 3) Oxygen

Explanation:

Biomolecules are organic compounds essential to life, composed primarily of carbon (C), hydrogen (H), and oxygen (O). These molecules form the structural and functional basis of living organisms. In addition to these elements, some biomolecules may also contain nitrogen (N), phosphorus (P), sulfur (S), and other trace elements.

Hence, the correct answer is option 3) Oxygen.

Q3. Lecithin, a small molecular weight organic compound found in living tissues, is an example of:

1. Amino acids

2. Phospholipids

3. Glycerides

4. Carbohydrates

Correct answer: 2) Phospholipids

Explanation:

Some lipids have phosphorus and a phosphorylated organic compound in them. These are phospholipids. They are found in cell membranes. Lecithin is one example.

Option (3) is incorrect, as glycerides are another group of lipids in which both glycerol and fatty acids are present.

Option (1) and (4) are incorrect as amino acids and carbohydrates are separate groups of biomolecules.

Hence, The correct answer is option 2) Phospholipids.

Also Read:

• MCQs on Biomolecules

• Factors Affecting Enzyme Activity

• Beriberi

Recommended Video on Biomolecules