This video is a detailed lecture on Biochemistry, specifically focusing on Polysaccharides and Lipids, presented by IFAS Lifescience for students preparing for exams like CSIR NET JRF, GATE, IIT JAM, CUET and DBT. IFAS: India's No. 1 Institute for CSIR NET, GATE, SET, DBT, BARC, ICMR & other PhD Life Science Entrance Examinations! India’s No.1 Results by IFAS. Download, and share with your friends! https://drive.google.com/file/d/19lIO... Stuck somewhere? 📞 Call us on: 9172266888 📞 WhatsApp: https://api.whatsapp.com/send?phone=9... 🌐 Visit on: https://ifasonline.com Detailed Time Stamps & Summary I. Polysaccharides [00:14] [00:26] Definition of polysaccharides as many sugars linked by glycosidic linkages. [02:20] Homo-polysaccharides: Composed of a single type of sugar (e.g., starch, glycogen, cellulose, chitin). [03:50] Hetero-polysaccharides: Yield two or more types of monosaccharides upon hydrolysis (e.g., heparin, chondroitin). [05:37] Functional classification: Storage (energy) vs. Structural (cell walls). II. Storage Polysaccharides [07:05] [07:45] Starch: The preferred energy storage in plants. Amylose: Linear polymer with α 1-4 linkages [09:27]. Amylopectin: Branched structure with α 1-4 and α 1-6 linkages [10:07]. [14:18] Glycogen: Energy storage in animals (liver and muscles). Highly branched compared to starch. [18:13] Inulin: Polymer of fructose used to assess Glomerular Filtration Rate (GFR) in kidneys [20:06]. III. Structural Polysaccharides [21:35] [21:52] Cellulose: Most abundant biomolecule; β 1-4 linkages make it indigestible for most animals without symbiotic microbes [25:51]. [30:49] Chitin: Polymer of N-acetyl-D-glucosamine; found in insect exoskeletons and fungal cell walls. [35:26] Pectin: Component of the middle lamella in plants; important in fruit ripening (degraded by polygalacturonase) [39:53]. IV. Lipids & Fatty Acids [56:07] [57:27] Definition of lipids based on solubility (low in water, high in non-polar solvents). [01:02:44] Why lipids are preferred for energy storage: yield more energy (9 kcal/g) and occupy less space (hydrophobic). [01:08:03] Fatty Acids: Long aliphatic chains with a carboxyl group. Saturated: No double bonds; melting point increases with chain length [01:13:53]. Unsaturated: Contain double bonds (mostly cis orientation, which introduces "kinks") [01:18:41]. [01:24:54] Essential Fatty Acids: Polyunsaturated fatty acids (PUFAs) like Omega-3 and Omega-6 that animals cannot synthesize. V. Lipid Signaling & Membrane Lipids [01:30:09] [01:31:27] Eicosanoids: Derived from Arachidonic acid; includes prostaglandins (inflammation/pain) and thromboxanes (blood clotting) [01:32:12]. [01:39:02] Soaps & Detergents: Amphipathic molecules that form micelles to remove stains [01:40:04]. [01:48:40] Membrane Lipids: Phospholipids, glycolipids, and sphingolipids. [01:58:20] Phosphatidylcholine (Lecithin): Acts as a lung surfactant (DPPC) [01:59:18]. [02:04:19] Phosphatidylinositol (PIP2): Precursor for secondary messengers like IP3 and DAG [02:05:11]. [02:07:38] Cardiolipin: Unique to the inner mitochondrial membrane. VI. Sphingolipids & Clinical Disorders [02:15:20] [02:17:43] Sphingomyelin: Found in high amounts in the myelin sheath. [02:22:25] Glycosphingolipids: Cerebrosides and Gangliosides (receptors for toxins and viruses) [02:24:27]. [02:25:15] Lipid Storage Diseases: Brief mention of Niemann-Pick, Gaucher, and Tay-Sachs diseases.