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: Physiology
[{'content': 'Which of the following best describes angiotensin conveing enzyme? \nSelect and explain. \nA. It is a Zinc containing enzyme and cleaves C-terminal of AT 1, B. It is a Zinc containing enzyme and cleaves the signal poion of AT-1, C. It is a Copper containing enzyme and cleaves C-terminal of AT 1, D. It is a Copper containing enzyme and cleaves the signal poion of AT-1', 'role': 'user'}, {'content': "Answer: A \nExplanation: Angiotensin conveing enzyme is a zinc containing protease that cleaves carboxy terminus dipeptides from from angiotensin I and bradykinin. Also know: Angiotensin conveing enzyme is a dipeptidyl carboxypeptidase which splits off histidyl-leucine from the physiologically inactive angiotensin I forming the octapeptide angiotensin II. It also inactivates bradykinin. ACE is an ectoenzyme which exists in two forms i.e a somatic form found throughout the body and a germinal form found in postmeiotic spermatogenic cells and spermatozoa. Germinal ACE is a 90-kDa protein that has only one extracellular domain and active site. Somatic ACE is a 170-kDa protein with two homologous extracellular domains, each containing an active site. Ref: Ganong's Review of Medical Physiology, 24e, chapter 38", 'role': 'assistant'}]