Biochemistry

All of the following are true EXCEPT

Absence from the diet of ceain amino acids that are present in most proteins is not deleterious to human health

Tetrahydrobiopterin is involved in tryptophan biosynthesis

Selenocysteine is an essential component of several mammalian proteins

Intermediates of the citric acid cycle and of glycolysis acts as precursors of aspaate, asparagine, glutamate, glutamine, glycine, and serine