This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Biochemistry
[{'content': 'Which of the following act through tyrosine kinase receptor? \nSelect and explain. \nA. Insulin, B. Glucagon, C. Growth hormone, D. Follicle stimulating hormone', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Insulin act by binding to plasma membrane receptors on the target cellsHas 2 alpha subunit and 2 beta subunitBeta subunit has tyrosine kinase activity Interaction of insulin with receptor alpha subunit triggers a conformational change, which is propagated to the beta subunit and activates itRef: DM Vasudevan, 7th edition, page no: 319', 'role': 'assistant'}]