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': 'The collagen triple helix structure is not found in - \nSelect and explain. \nA. Cytoplasm, B. Golgi apparatus, C. Lumen of endoplasmic reticulum, D. Intracellular vesicles', 'role': 'user'}, {'content': "Answer: A \nExplanation: Triple helix formation occurs in endoplasmic reticulum at procollagen level.\nTriple helix of procollagen is packed into\xa0secretory intracellular vesicles\xa0in the\xa0Golgi-apparatus.\nThese vesicles then secrete the procollagen into extracellular space where it is converted to tropocollagen (collagen monomer).\nTropocollagens aggregate into\xa0collagen fibrils\xa0which intern become extensively cross-linked to form\xa0'collagen fibers'.", 'role': 'assistant'}]