Physiology Because free ammonia in the blood is toxic to the body, it is transported in which of the following non-toxic forms? A Histidine and urea B Phenylalanine and methionine C Glutamine and urea D Lysine and glutamine 💡 Explanation Because free ammonia in the blood is toxic to the body, it is transported in which of the following non-toxic forms? ✓ Correct Answer: C. Glutamine and urea