Biomolecules

What are Biomolecules?

Biomolecules are defined as the most essential organic molecules involving in the maintenance and metabolic processes of living organisms. Biomolecules are organic compounds found in living organisms. These compounds include protein carbohydrates, lipids and nucleic acids. Together they play a very important role in biological process, storage of energy, maintenance of cell structure, and also carry genetic information. Biomolecules is a chapter from class 11. This chapter is also important for exams like NEET and AIIMS Nursing where Biology is one of the major Subjects asked.

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This Story also Contains

1. What are Biomolecules?
2. Biomolecules Examples
3. Biomolecules Functions
4. Synthesis and Breakdown of Biomolecules
5. Tips, Tricks, and Strategies to Prepare for Biomolecules
6. Types of Questions Asked on Biomolecules
7. Prescribed Books for Biomolecules

Important Topics of Biomolecules:

• Types of Biomolecules
• Functions of Biomolecules
• Biomolecules in Health and Diseases
• Important Concepts - Proteins, Carbohydrates, Lipids, Nucleic Acid, Enzymes

Overview of the Chapter

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

The various types of biomolecules are listed below

Carbohydrates

Definition and general structure of Carbohydrates:

• 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

• Monosaccharides (1 unit): For example, glucose is a kind of simple sugar and is also classified as a monosaccharide.
• Disaccharides (2 unit),
• The oligosaccharides (2-10 units) contain more than two monosaccharides but less than a polysaccharide like a sucrase.
• Polysaccharides (more than 10 units): 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 signalling.

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 of proteins:

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

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

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 of lipids:

• 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 oil.
• It is also important because it is a form of storage of energy and 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 or unsaturated fats.

Types

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

Functions

Lipids are involved in energy storage, 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 of nucleic acids:

• 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.
• 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

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.

Vitamins and Coenzymes

• Some of the small organic molecules that help the enzymes to do their job in the chemical reactions are known as co-enzymes.

• These are responsible for the overall metabolic speed and metabolism of our body.

Biomolecules Examples

• Proteins: Amylase ( enzymes), Collagen ( Structural protein)

• Carbohydrates: glucose and starch

• Lipids: triglycerides, phospholipids

• Nucleic acids: DNA and RNA

• Vitamin and coenzymes: vitamin C and coenzyme A

Biomolecules Functions

Some important functions of Biomolecules are discussed below:

Synthesis and Breakdown of Biomolecules

The process of synthesis and breakdown of biomolecules are discussed below:

Anabolic Pathways

Anabolic mechanisms are those biochemical reactions that involve synthesizing larger molecules from the smaller ones and for this process, energy is used.

These paths are concerned with the anabolic or biosynthetic processes through which large molecules for instance, proteins, nucleic acids, and polysaccharides are built from simpler molecules

Catabolic Pathways

Catabolic processes are the processes, in which there are conversions of large molecules into simple molecules with the liberation of energy.

This energy is normally used to drive various cellular activities. For instance, the breakdown of carbohydrates, fats, and proteins into ATP, is the principal energy currency of a cell.

Enzymatic Reactions in Synthesis and Degradation

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 is used to synthesize DNA and proteases which are used to deconstruct proteins into amino acids.

Examples of Metabolic Pathways

Glycolysis: A glycolytic sequence of reactions that involves the breakdown of one molecule of glucose into two molecules of pyruvate with the generation of ATP and NADH. It is the initial process in the sequence that is known as respiration in the cells.

Krebs Cycle: The Kreb cycle or citric acid cycle, is a catabolic process that breaks down pyruvate into ATP, NADH, and FADH2, all of which are energy molecules.

Protein Synthesis: This process includes DNA transcription to mRNA and mRNA translation to form polypeptides that are folded into functional proteins.

Biomolecules in Health and Diseases

The role of biomolecules in human health and diseases is discussed below:

Role of Biomolecules in Maintaining Health

Biomolecules are involved inter alia in the regulation of physiological processes leading to 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:

Diabetes

Diabetes is a disease of metabolism and is defined by a malfunction of glucose metabolism and increased blood sugar.

This condition stems from a lack of generated insulin as in the case of Type 1 diabetes or reduced insulin sensitivity in Type 2 diabetes patients blood glucose levels are high since glucose absorption and utilisation are affected under this condition

Hypercholesterolemia

Hypercholesterolemia is a situation that results from the high density of lipids and cholesterol in the blood and this may be a result of genetic or dietary matters.

This condition results in the formation of plaque in arteries and therefore exposes the patient to the possibility of heart attacks and/or strokes.

Phenylketonuria

PKU is a metabolism disorder that occurs when the body lacks enough of the enzyme called phenylalanine hydroxylase to properly metabolize phenylalanine.

Phenylalanine can harm the patient if it accumulates and causes intellectual disabilities and other neurological disorders if not under the Phenylketonuria diet.

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 patients’ benefits.

Tips, Tricks, and Strategies to Prepare for Biomolecules

It's hard to remember everything in a single go. We made the entire problem easy. Some of the tricks regarding Biomolecules are given below which you can use to memorize the important points.

Protein Structure Levels

PSTQ:

• P: Primary (Sequence of amino acids)

• S: Secondary (α-Helix or β-Sheets)

• T: Tertiary (3D structure)

• Q: Quaternary (Multiple polypeptide chains)

Enzyme Functions

HELPS

• H: Hydrolysis

• E: Electron transfer (oxidation-reduction)

• L: Ligase reactions (bond formation)

• P: Phosphorylation

• S: Synthesis (building up molecules)

Nucleotides (DNA and RNA bases)

A G C T for DNA:

• A: Adenine

• G: Guanine

• C: Cytosine

• T: Thymine

For RNA replace T with U (Uracil).

Types of Questions Asked on Biomolecules

During the preparation of the exam, there are different types of questions asked about Biomolecules in different forms. The table given below contains the different patterns of questions asked in different exams.

Prescribed Books for Biomolecules

NCERT Biology textbook class 11 forms the base for learning Biomolecules. Further extended understanding of the concept can be done through "Trueman's Elementary Biology, Volume 1", which provides all essential explanations with practice questions. Another helpful book is "Pradeep's Biology" which provides proper explanations with solved examples. Other great videos, articles, and practice mock tests are available on the Careers360 website for this topic.

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