Biochemistry Carboxylation of clotting factors by vitamin K is required to be biologically active. Which of the following amino acid is carboxylated? A Histidine B Histamine C Glutamate D Aspaate 💡 Explanation Carboxylation of clotting factors by vitamin K is required to be biologically active. Which of the following amino acid is carboxylated? ✓ Correct Answer: C. Glutamate