Introduction to Biomolecules for JEE Main

The chapter Biomolecules is an important part of Class 12 Chemistry, forming a bridge between organic chemistry and biology. This chapter is crucial for JEE Main aspirants, as questions are often asked on structure, reactions, and functions of biomolecules.

Biomolecules include carbohydrates, proteins, nucleic acids, vitamins, and hormones, which are essential for living systems. Understanding their chemistry helps solve both conceptual and application-based questions.

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Carbohydrates – Structure and Classification

Carbohydrates are polyhydroxy aldehydes or ketones.

Classification:

• Monosaccharides: Glucose, Fructose, Galactose

• Disaccharides: Sucrose, Lactose, Maltose

• Polysaccharides: Starch, Cellulose, Glycogen

Properties and Reactions:

• Reducing vs non-reducing sugars

• Benedict’s test, Fehling’s test

• Hydrolysis of disaccharides and polysaccharides

Carbohydrates are often asked in reaction-based MCQs in JEE Main.

Proteins – Structure and Classification

Proteins are polymers of amino acids linked by peptide bonds.

Classification:

• Simple proteins (albumins, globulins)

• Conjugated proteins (glycoproteins, lipoproteins)

Levels of protein structure:

• Primary, Secondary (α-helix, β-sheet)

• Tertiary, Quaternary

Reactions of proteins:

• Biuret test

• Xanthoproteic test

• Ninhydrin test

Mechanism of peptide bond formation is important for JEE Main.

Nucleic Acids – DNA and RNA

Nucleic acids are polymers of nucleotides, each containing a nitrogenous base, sugar, and phosphate group.

Structure:

• DNA: Double helix, complementary base pairing

• RNA: Single-stranded, types – mRNA, tRNA, rRNA

Functions:

• DNA stores genetic information

• RNA helps in protein synthesis

Questions may involve base pairing, structures, or nucleotides.

Vitamins – Classification and Functions

Vitamins are organic compounds required in small amounts for metabolic processes.

Classification:

• Fat-soluble: A, D, E, K

• Water-soluble: B-complex, C

Functions:

• Vitamin A – vision

• Vitamin D – bone health

• Vitamin K – blood clotting

• Vitamin C – antioxidant

MCQs may test deficiency diseases or classification.

Hormones – Classification and Functions

Hormones are chemical messengers that regulate body processes.

Classification:

• Peptide hormones (insulin, glucagon)

• Steroid hormones (testosterone, estrogen)

• Amine hormones (adrenaline, thyroxine)

Functions include growth regulation, metabolism, and homeostasis.

Enzymes – Biological Catalysts

• Enzymes are proteins that catalyze biochemical reactions

• Substrate specificity and active site concept

• Factors affecting enzyme activity: pH, temperature, inhibitors

JEE Main may ask enzyme classification or mechanism of action.

Comparison Between Biomolecules

Comparison-based MCQs are often included in JEE Main.

Applications of Biomolecules

• Carbohydrates: Energy source and storage

• Proteins: Enzymes, hormones, structural components

• Nucleic acids: Genetic information transfer

• Vitamins & Hormones: Regulation of metabolism, growth, and health

Conceptual and application-based questions are common in JEE Main.

Important JEE Main Preparation Tips for Biomolecules

• Focus on structure, tests, and reactions

• Memorize classification and functions

• Solve previous year questions on deficiency diseases and reaction tests

• Practice diagrams for DNA, RNA, and protein structures

Why Study Biomolecules from Studentbro.in?

Studentbro.in provides:

• Step-by-step explanations of complex reactions

• Tables and charts for easy memorization

• MCQs and PYQs for practice

• Exam-oriented content aligned with JEE Main syllabus

Conclusion

The Biomolecules chapter is crucial and scoring in Class 12 Chemistry for JEE Main. A clear understanding of carbohydrates, proteins, nucleic acids, vitamins, and hormones helps students answer mechanism, application, and conceptual questions efficiently.

Studentbro.in offers structured, easy-to-understand, and exam-focused content to master Biomolecules efficiently.