What does the enzyme glutamine synthetase primarily catalyze?

Glutamine synthetase is an important enzyme in amino acid metabolism, specifically responsible for catalyzing the conversion of glutamate into glutamine. This reaction is crucial because glutamine serves as a key nitrogen donor in various biosynthetic pathways and plays an essential role in nitrogen metabolism and energy production. The enzyme uses ATP to facilitate this reaction, thereby incorporating an amine group into glutamate, effectively producing glutamine. Glutamine is vital for many physiological processes, including protein synthesis, nucleotide synthesis, and maintaining acid-base balance in the kidneys. The action of this enzyme highlights the importance of glutamine in cellular functions and the nitrogen cycle.