Detoxification of Ammonia
A 60 years old women suffers from cirrhosis of liver. Toxins such as ammonia are not properly metabolized by the liver and can damage brain. Which of the following compounds should be in highest concentration in brain as result of detoxification of ammonia?
a. Alpha ketoglutarate
b. Glutamine
c. Glutamate
d. Gamma amino butyric acid
e. Asparagine
ANSWER IS B : Glutamine will be found in highest concentration in brain as ammonia is detoxified
The ammonia in our body is produced as a result of metabolic activities that take place within the body. Ammonia is a toxin and if it is not being eliminated from the body, it can damage brain. Firstly, glutamate will combined with ammonia in order to form glutamine. Next, the glutamine produced will be sent to liver. The nitrogen in glutamine will be converted to urea in liver. So, ammonia is released as urine and leave the body.
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If the ammonia is still in excess, alpha ketoglutarate in liver will be converted to glutamate and later glutamate will be converted to glutamine. Once ammonia detoxification accomplished, the glutamine will be transported out of the brain cells in exchange with tryptophan.
In this detoxification process, glutamate and alpha ketoglurate will decrease in number as they are converted to glutamine. Low number of glutamate will produce less number of gamma amino butyric acid. Asparagine is not really affected in this process. |