Lecture On Passive Transport Mechanisms: Simple Diffusion, Facilitated Diffusion & Osmosis | MBBS

🧬 Master Passive Transport Across the Cell Membrane!This essential physiology lecture by Dr. Balaram Sutradhar from Tripura Santiniketan Medical College (TSMC) is a comprehensive resource for MBBS, BDS, and Life Science students seeking to understand the energy-independent movement of molecules across the fluid mosaic model of the cell membrane.We provide a detailed breakdown of Simple Diffusion, Facilitated Diffusion (using carrier and channel proteins), and Osmosis, exploring the factors that influence the rate of transport and the principles of Fick's Law of Diffusion.📝 Lecture Content & Timestamps (Table of Contents)Use the chapters below to navigate the core concepts of passive cellular transport:[00:43] Importance of Cell Transport: Essential for chemical reactions, waste elimination, and generating membrane potential.[03:14] Structural Basis of Transport: Review of the Phospholipid Bilayer (Polar Head, Non-Polar Tail) and Membrane Proteins (Extrinsic, Intrinsic, and Integral/Transmembrane Proteins). * [11:09] Classification of Transport: Passive Transport (Energy Independent) vs. Active Transport (Energy Dependent).[12:12] I. Simple Diffusion:[14:36] Mechanism: Movement along the concentration gradient (High to Low).[15:23] Molecules Transported: Lipid-soluble substances (Gases like O₂, CO₂, Steroid Hormones) and small, uncharged molecules (Water).[17:31] Protein Channels in Diffusion:[17:41] Leaky/Open Channels: Always open (e.g., K+ Leak Channels).[19:32] Gated Channels: Ligand-Gated (requires binding of a signaling molecule) and Voltage-Gated (responds to changes in electrical potential).[24:50] Factors Affecting Diffusion Rate:Molecular Factors: Lipid Solubility, Size/Molecular Weight, Temperature.Membrane Factors: Thickness, Surface Area.Gradient Factors: Concentration, Pressure, Electrical Gradient.[27:09] Fick's Law of Diffusion: Formula used to calculate the rate of diffusion (Q) based on concentration difference, surface area, and membrane permeability.[28:38] II. Facilitated Diffusion (Carrier-Mediated):[28:58] Mechanism: Requires a Carrier Protein (like Glut Transporter for glucose).[30:22] Saturation Kinetics: Why the transport rate reaches a maximum velocity ($V_{max}$) due to the limited number of carrier proteins. * [33:48] Peculiarities: Specificity, Competition, and Inhibition.[36:26] III. Osmosis:[36:35] Mechanism: Movement of Solvent (Water) across a semi-permeable membrane from High Solvent Concentration (Low Solute) to Low Solvent Concentration (High Solute).PHYSIOLOGY & CELL BIOLOGY KEYWORDS (For SEO)Passive Transport, Cell Membrane Transport, Simple Diffusion, Facilitated Diffusion, Osmosis, Fick's Law of Diffusion, Fick's Principle, Carrier-Mediated Transport, Channel Proteins, Ligand-Gated Channels, Voltage-Gated Channels, Membrane Potential, Saturation Kinetics, Phospholipid Bilayer, MBBS Lecture.CONNECT WITH USChannel: Tripura Santiniketan Medical College (TSMC)Lecturer: Dr. Balaram SutradharSubscribe for more Physiology lectures: [Channel Link Placeholder]#physiology #cellbiologycsirnetlifescience #PassiveTransport #Diffusion #Osmosis #MBBS #MedicalEducation #mbbsclass #medical #class #education #mbbs #TSMC #students TRIPURA SANTINIKETAN MEDICAL COLLEGE Real Classroom Demonstration/Lecture PHYSIOLOGY LECTURE ON- TRANSPORT ACROSS CELL MEMBRANE. BY-DR. BALARAM SUTRADHAR (MBBS Batch: 2025-26) Conducted on: 03-11-25