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: Biochemistry
[{'content': 'Cholesterol present in LDL \nSelect and explain. \nA. Represents primarily cholesterol that is being removed from peripheral cells, B. Binds to a receptor and diffuses across the cell membrane, C. On accumulation in the cell inhibits replenishment of LDL receptors, D. When enters a cell, suppresses activity of acyl-CoA; cholesterol acytransferase ACAT', 'role': 'user'}, {'content': 'Answer: C \nExplanation: On accumulation in the cell inhibits replenishment of LDL receptors\n\nIf LDL cholesterol is increased inside the cell, it down regulates LDL receptors so that further uptake is inhibited.\nHDL cholesterol is the cholesterol that is removed from peripheral tissues; LDL cholesterol represents the cholesterol which is to be delivered to peripheral tissues.\nLDL binds to LDL receptors and whole LDL particle is endocytosed by receptor mediated endocytosis via clathrin-coated pits (not by diffusion:- diffusion and endocytosis are different processes).\nIntracellular cholesterol activates intracellular enzyme acyl-CoA cholesterol acyl transferase (ACAT).', 'role': 'assistant'}]