In the alanine cycle, what happens to alanine after being taken up by the liver?

In the alanine cycle, alanine plays a significant role in the transport of nitrogen and the regulation of glucose levels, particularly during fasting or intense exercise. Once alanine is taken up by the liver, it undergoes deamination, which is the process of removing an amino group from the amino acid. This reaction converts alanine into pyruvate, which can then enter gluconeogenesis, a metabolic pathway that produces glucose from non-carbohydrate sources.

This is crucial for maintaining blood glucose levels, especially during periods when the body needs energy but carbohydrate availability is low. The glucose produced can then be released into the bloodstream to be used as an energy source by other tissues, especially the muscle and brain. Hence, the transformation of alanine in the liver through deamination to ultimately release glucose is a key metabolic pathway in the alanine cycle.

Other options do not align with the primary metabolic fate of alanine in the liver during the alanine cycle. The excretion of alanine in urine would not be the primary pathway, as metabolic processing is preferred. The conversion into adipose tissue typically involves fatty acids, not amino acids like alanine. Lastly, oxidation of alanine to nitric acid does not occur, as alanine’s fate is