Final answer:
Glutamate and Glutamine are synthesized from the TCA cycle intermediate α-Ketoglutarate, which serves as a crucial link between nitrogen and carbon metabolism.
Step-by-step explanation:
Glutamate and Glutamine are synthesized from the tricarboxylic acid (TCA) cycle intermediate α-Ketoglutarate. This compound is a key player in the metabolism of amino acids and serves as a fulcrum connecting nitrogen and carbon metabolism. During the process of oxidative deamination, glutamate can be transformed into α-Ketoglutarate, which can then enter the TCA cycle to produce energy. Conversely, α-Ketoglutarate can also be aminated to form glutamate, which may then be converted to glutamine. This relationship exemplifies the essential role of α-Ketoglutarate as both a TCA cycle intermediate and a substrate for amino acid synthesis.