This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
[{'content': 'The protein in glomerular basement membrane responsible for charge dependent filtration is - \nSelect and explain. \nA. Albumin, B. Collagen type IV, C. Proteoglycan, D. Fibronectin', 'role': 'user'}, {'content': "Answer: C \nExplanation: Structure of glomerulus \n\nThe glomerulus is composed of an anastomosing network of capillaries lined by fenestrated endothelium invested by two layers of epithelium.\nThe visceral epithelium (podocytes) is incorporated into and becomes an intrinsic part of the capillary wall, separated from endothelial cells by basement membrane.\nThe parietal epithelium, situated on Bowman's capsule, lines the urinary space.\nThe glomerular capillary wall is the filtering membrane and consist of the following structures.\n\n\nA thin layer of fenestrated endothelial cells.\nGlomenilar basement membrane (GBM).\nVisceral epithelium (Podocytes) →\xa0their adjacent foot processes are separated by filtration slits.\nMesangial matrix and mesangial cells support the entire glomerular tuft.\n\nGlomerular barrier function \n\nThe filtration of any substance through glomerular filtration layer depends on two factors -\n\nA.\xa0 Size of the substance\n\nGlomerular filtration layer is more porous than another capillary membrane.\nAny neutral substance <4A diameter freely filters through this layer\n\nB.\xa0 The charge of the substance\n\nThe acidic glycoprotein of the GBM and the acidic sialoglycoprotein\xa0of epithelial and endothelial cell coats are negatively charged (anionic).\nTherefore all anionic molecules (negatively charged) including albumin are repelled by the filtration layer.\n\nSo,\n\nThe larger the molecule\xa0→ less permeable\nThe more cationic the protein → more permeable", 'role': 'assistant'}]