Metabolism | Glycogenolysis

Official Ninja Nerd Website: https://ninjanerd.org Ninja Nerds! In this metabolism lecture, Professor Zach Murphy presents on Glycogenolysis, the catabolic pathway responsible for breaking down stored glycogen into glucose to meet energy demands during fasting, exercise, or stress. This lecture complements glycogenesis by showing how the body mobilizes internal glucose reserves to maintain blood glucose levels and support ATP production. We begin by walking through the stepwise degradation of glycogen, starting with the action of glycogen phosphorylase, which cleaves α(1,4) glycosidic bonds to release glucose-1-phosphate. You’ll also learn how the debranching enzyme resolves α(1,6) linkages to fully liberate glucose units. These products are then funneled into glycolysis or released into the bloodstream, particularly by the liver. The lecture highlights key regulatory mechanisms, including hormonal control by glucagon and epinephrine, which activate glycogen phosphorylase via phosphorylation cascades involving protein kinase A (PKA). In contrast, insulin suppresses glycogenolysis by promoting dephosphorylation of key enzymes. We also distinguish between liver and muscle glycogenolysis, noting how muscle glycogen supports local energy needs without contributing to blood glucose. Enjoy the lecture and support us below! 🌐 Official Links Website: https://www.ninjanerd.org Podcast: https://podcast.ninjanerd.org Store: https://merch.ninjanerd.org 📱 Social Media   / ninjanerdlectures     / ninjanerdlectures     / ninjanerdlectures   https://x.com/ninjanerdsci/   / ninja-nerd   💬 Join Our Community Discord:   / discord   #ninjanerd #Glycogenolysis #Metabolism