3. Connective Tissue Biochemistry | Collagen Structure, Synthesis & Clinical Aspects | USMLE Step 1 скачать в хорошем качестве

3. Connective Tissue Biochemistry | Collagen Structure, Synthesis & Clinical Aspects | USMLE Step 1

𝐒𝐮𝐛𝐬𝐜𝐫𝐢𝐛𝐞 𝗙𝐨𝐫 𝗠𝐨𝐫𝐞 𝗜𝐧𝐟𝐨𝐫𝐦𝐚𝐭𝐢𝐨𝐧 𝐨𝐧 𝗛𝐞𝐚𝐥𝐭𝐡 👩‍⚕‍ 𝐚𝐧𝐝 𝗠𝐞𝐝𝐢𝐜𝐢𝐧𝐞💉🩺💊 📌𝗜𝗻𝘀𝘁𝗮𝗴𝗿𝗮𝗺 :   / clinical.learning   Connective Tissue Biochemistry | Collagen Structure, Synthesis & Clinical Aspects | MBBS | USMLE Step 1 Hey future doctors and biochem enthusiasts! Did you know that collagen is the body’s main structural protein, forming the framework of skin, bone, cartilage, tendons, and blood vessels? 🦴🩺 In this lecture, we’ll dive into the structure of collagen, the step-by-step process of collagen biosynthesis, and applied clinical aspects — a topic that is high-yield for MBBS, NEET PG, FMGE, and USMLE Step 1. 🧬📚 🌟 Collagen Structure Primary structure: Rich in glycine, proline, and hydroxyproline (Gly every 3rd residue). Secondary/tertiary structure: Left-handed helix. Quaternary structure: Triple helix of 3 polypeptide chains (tropocollagen). Types of collagen: • Type I → Bone, skin, tendon (most common). • Type II → Cartilage. • Type III → Reticular fibers, blood vessels (first affected in Ehlers–Danlos). • Type IV → Basement membrane (defective in Alport syndrome, Goodpasture syndrome). 🌟 Collagen Synthesis (Stepwise) 1️⃣ In the RER (Intracellular phase): Synthesis of pre-procollagen. Hydroxylation of proline & lysine (requires Vitamin C). Glycosylation of hydroxylysine. Formation of triple helix → procollagen. 2️⃣ In the Golgi & Extracellular space: Procollagen secreted → cleaved to tropocollagen. Tropocollagen molecules assemble into fibrils. Cross-linking by lysyl oxidase (requires copper) → mature collagen fibers. 🩺 Clinical Correlations Scurvy (Vitamin C deficiency): Defective hydroxylation → weak collagen → bleeding gums, poor wound healing. Ehlers–Danlos syndrome: Defective collagen synthesis → hyperextensible skin, hypermobile joints, vessel fragility. Osteogenesis imperfecta: Type I collagen defect → brittle bones, blue sclera, hearing loss. Alport syndrome: Type IV collagen defect → hematuria, hearing loss, ocular abnormalities. Menkes disease: Copper deficiency → impaired lysyl oxidase → weak connective tissue. 🎯 Exam Integration Mnemonic for Collagen Types: “Strong, Slippery, Stretchy, Basement” → Types I–IV. Rate-limiting step: Hydroxylation (Vit C dependent). Key enzymes: Prolyl hydroxylase, Lysyl hydroxylase, Lysyl oxidase. 👉 A favorite topic for both recall and clinical vignette questions in USMLE Step 1 & NEET PG. 👉 Don’t forget to Subscribe and tap the 🔔 bell for more high-yield medical biochemistry lectures! 👍 If this lecture helps you, give it a like and share it with your classmates. Your support motivates us to keep making simplified, exam-focused content. 🙌 ❓Want us to make a separate video on Collagen Disorders (Scurvy, OI, Ehlers–Danlos, Alport) with clinical cases and pathology integration? Drop your request in the comments below! 😊 #Collagen #ConnectiveTissue #MedicalBiochemistry #USMLEStep1 #MBBSLectures #FMGE #NEETPG #CollagenSynthesis #Scurvy #EhlersDanlos #OsteogenesisImperfecta #AlportSyndrome #MenkesDisease #TripleHelix #ProteinStructure #BiochemistryLecture #MedicalStudents