This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunology, Subject name: Microbiology
[{'content': 'C-3 convease in alternate complement pathway - \nSelect and explain. \nA. C4b2b, B. C3b, C. C3bBb, D. C3a', 'role': 'user'}, {'content': "Answer: C \nExplanation: - the first step in the alternative pathway is the binding of C3b to an activator. - bound C3b , which is protected from such inactivation, interact with Factor B to form a magnesium dependent complex C3bB. - this complex is cleaved by Factor D into two fragments, Ba and Bb. -fragment Ba is released into medium. - fragment Bb remains bound to C3b, forming the esterase C3bBb complex, which is alternative pathway C3 convease. Reference : Anathanarayan & paniker's 9th edition, pg no:123 <\\p>", 'role': 'assistant'}]