How is ammonia transported in the body?

Ammonia is primarily transported in the body in the form of L-glutamine, which efficiently reduces its potential toxicity. The conversion of ammonia to L-glutamine occurs through a reaction catalyzed by the enzyme glutamine synthetase, which combines ammonia with L-glutamate. This reaction not only facilitates the safe transport of ammonia but also plays a critical role in nitrogen metabolism.

L-glutamine serves as a stable and non-toxic form of ammonia transport that can traverse various tissues and ultimately reach the liver, where it can be utilized in the urea cycle for detoxification. This mechanism is especially important given the high toxicity of ammonia, particularly to the central nervous system, thus ensuring that it is effectively and safely handled within the body.

Other methods of transporting nitrogen, such as via direct conversion to urea or attaching to glucose, do not account for the biological roles and safety mechanisms in nitrogen metabolism, and transporting unbound ammonia in the bloodstream poses a significant risk due to its toxicity. The utilization of L-glutamine as a transport form aligns with the body's need to manage ammonia levels thoughtfully and effectively.