905612.fig.003
Figure 3: The urea cycle of the liver, showing the connections between the TCA cycle in the mitochondria, ammonia, and the production of urea. Note that the conversion of glutamate to α-ketoglutarate (top central region of figure) is condensed for clarity ( o x a l o a c e t a t e + g l u t a m a t e 𝛼 - k e t o g l u t a r a t e + a s p a r t a t e [aspartate aminotransferase]) and is therefore also a source of aspartate. The direct conversion of glutamate to α-ketoglutarate is catalyzed by glutamate dehydrogenase.