This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: vitamins, Subject name: Biochemistry
[{'content': 'Carboxylation of clotting factors by vitamin K is required to be biologically active. Which of the following amino acid is carboxylated? \nSelect and explain. \nA. Histidine, B. Histamine, C. Glutamate, D. Aspaate', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Vitamin K has an impoant role in the blood clotting process. It brings about the posttranslational modification of ceain blood clotting factors clotting factor II, VII, IX, X Vitamin K is required for the post-translational carboxylation of glutamic acid (Gamma Carboxylation), which is necessary for calcium binding to g carboxylated proteins clotting factors are synthesized as inactive precursors (zymogens) in the liver ref DM Vasudevan 8th ed page 462', 'role': 'assistant'}]