<unk>  <unk> ,<unk>  is an enzyme observed in both prokaryotes and eukaryotic mitochondria. The aforementioned reaction also yields ammonia, which in eukaryotes is canonically processed as a substrate in the urea cycle. Typically, the α-ketoglutarate to<unk>  reaction does not occur in mammals, as<unk>  equilibrium favours the production of ammonia and α-ketoglutarate.<unk>  also has a very low affinity for ammonia (high Michaelis constant of about 1 mM), and therefore toxic levels of ammonia would have to be present in the body for the reverse reaction to proceed (that is, α-ketoglutarate and ammonia to<unk>  and NAD(P)+). However, in brain, the NAD+/NADH ratio in brain mitochondria encourages oxidative deamination (i.e.<unk>  to α-ketoglutarate and ammonia). In bacteria, the ammonia is assimilated to amino acids via<unk>  and aminotransferases. In plants, the enzyme can work in either direction depending on environment and stress. Transgenic plants expressing microbial<unk> s are improved in tolerance to herbicide, water deficit, and pathogen infections. They are more nutritionally valuable. The enzyme represents a key link between catabolic and anabolic pathways, and is, therefore, ubiquitous in eukaryotes. In humans the relevant genes are called<unk> <unk>  1) and<unk> <unk>  2), and there are also at least 8<unk>  pseudogenes in the human genome as well, probably reflecting microbial influences on eukaryote evolution. Image:Glutaminsäure - Glutamic acid.Glutamate Image:Alpha-ketoglutaric acid.α-Ketoglutarate
Glutamate dehydrogenase
Aldehyde dehydrogenase
Phenylalanine hydroxylase
Tyrosine hydroxylase
Acyl-CoA dehydrogenase
Monoamine oxidase B
Pyruvate carboxylase
Aromatic L-amino acid decarboxylase