18. Uronic Acid Pathway– Reactions & Clinical Significance | Biochemistry | USMLE High-Yield Lecture скачать в хорошем качестве

18. Uronic Acid Pathway– Reactions & Clinical Significance | Biochemistry | USMLE High-Yield Lecture

𝐒𝐮𝐛𝐬𝐜𝐫𝐢𝐛𝐞 𝗙𝐨𝐫 𝗠𝐨𝐫𝐞 𝗜𝐧𝐟𝐨𝐫𝐦𝐚𝐭𝐢𝐨𝐧 𝐨𝐧 𝗛𝐞𝐚𝐥𝐭𝐡 👩‍⚕‍ 𝐚𝐧𝐝 𝗠𝐞𝐝𝐢𝐜𝐢𝐧𝐞💉🩺💊 📌𝗜𝗻𝘀𝘁𝗮𝗴𝗿𝗮𝗺 :   / clinical.learning   Uronic Acid Pathway– Reactions & Clinical Significance | Biochemistry | USMLE High-Yield Lecture This high-yield video covers the Uronic Acid Pathway, a lesser-known but clinically important alternative route of glucose metabolism. Though it doesn’t directly yield ATP, this pathway plays a crucial role in the biosynthesis of glycosaminoglycans (GAGs), glucuronic acid, and detoxification via conjugation reactions. For USMLE Step 1, it's often tested indirectly through applied clinical concepts like bilirubin metabolism, drug detoxification, and inherited disorders like essential pentosuria. 🧠🧬 🌀 Key Reactions of the Uronic Acid Pathway: – Begins with glucose-6-phosphate, which is converted to glucuronic acid via intermediate steps involving UDP-glucose and UDP-glucuronic acid – Important branching point from glycolysis, sharing early steps with the hexose monophosphate shunt – Forms:  • UDP-glucuronic acid – used in conjugation of bilirubin, drugs, and xenobiotics  • Ascorbic acid (vitamin C) in some animals (but not in humans due to lack of L-gulonolactone oxidase)  • Pentoses, like xylulose, in a non-oxidative manner ⚙️ Functions & Importance: – Detoxification: UDP-glucuronic acid conjugates with bilirubin, hormones, and drugs, making them more water-soluble for excretion via bile or urine – Structural Role: Provides glucuronic acid for glycosaminoglycan (GAG) synthesis — essential for connective tissue, cartilage, and extracellular matrix – Pentose production: In individuals with G6PD deficiency, this pathway may compensate by generating pentoses independent of the oxidative PPP 🩺 Clinical Relevance: – Essential Pentosuria: A benign condition due to deficiency of xylitol dehydrogenase, leading to urinary excretion of L-xylulose — may mimic diabetes on urine tests – Crigler-Najjar Syndrome & Gilbert Syndrome: Disorders of bilirubin conjugation, involving UDP-glucuronosyltransferase, not the uronic acid pathway directly but dependent on its product – Detoxification failure in liver disease or with enzyme inhibition can impair glucuronide conjugation, leading to drug toxicity or jaundice This lecture helps you connect pathway biochemistry with clinical concepts, ensuring you’re ready for integrated USMLE Step 1 questions involving bilirubin metabolism, pharmacology, and metabolic pathways that don't directly yield energy but are still crucial for homeostasis. #UronicAcidPathway #USMLEStep1 #BiochemistryReview #GlucuronicAcid #BilirubinConjugation #Detoxification #EssentialPentosuria #GAGs #NBMEReview #Step1Prep #WhiteboardMedicine #DrGBhanuPrakash #USMLEBuzzwords #MetabolicPathways #VitaminC #HexoseMonophosphateShunt #MedicalEducationUSA #USMLE2025