Clear breakdown of Haworth structures, D/L configuration, essential amino acids, and nucleic acid base pairing.
Biomolecules connects organic chemistry with biological function. Studying carbohydrates, proteins, enzymes, vitamins, and nucleic acids provides essential scoring conceptual points in Class 12 Chemistry.
Carbohydrates: Monosaccharides (Glucose, Fructose), Oligosaccharides (Sucrose, Lactose, Maltose), and Polysaccharides (Starch, Cellulose, Glycogen). Glucose structure evidence: HI reduction gives n-hexane; Hydroxylamine gives oxime; Nitric acid oxidation gives saccharic acid. Sucrose is a non-reducing sugar showing Invert Sugar behavior upon hydrolysis.
Proteins & Amino Acids: Amino acids contain both amino (-NH2) and carboxyl (-COOH) groups, existing as dipolar Zwitterions. Peptide bonds (-CO-NH-) link amino acid units. Protein structure levels: Primary (sequence), Secondary (alpha-helix, beta-pleated sheet), Tertiary (3D folding), and Quaternary. Denaturation destroys 2° and 3° structures while keeping 1° structure intact.
Nucleic Acids: DNA and RNA composed of pentose sugar, phosphoric acid, and nitrogenous bases. DNA contains Adenine, Guanine, Cytosine, and Thymine; RNA contains Uracil in place of Thymine. Complementary base pairing: A=T (2 hydrogen bonds) and G#C (3 hydrogen bonds). Dr. Aarzoo Saini simplifies biomolecule structures at We-Gyaan Classes Roorkee.
Key Takeaways for Students
- Master chemical reactions proving open-chain and cyclic Haworth structures of Glucose.
- Understand Zwitterion formation and amphoteric behavior of amino acids.
- Differentiate primary, secondary, and tertiary structures of proteins during denaturation.
- Remember complementary base pairing rules: A-T (2 H-bonds) and G-C (3 H-bonds).
Authored by Dr. Aarzoo Saini
Founder & Lead Educator at We-Gyaan Classes Roorkee, with over 20 years of teaching excellence in Science and Chemistry for Board Exams, NEET, JEE, and CUET.