Synthesis amino acid plants
This is a fundamental idea in determining biochemical pathways. Enzymic reaction between arginine and fumarate in plant and animal tissues.
Amino Acid Biosynthesis
L - Methionine is precursor of ethylene and of growth factors such as Espermine and Espermidine, which are synsthesized from 5 - Adenosyl Methionine. Google Scholar Davison, D.
Heme is iron bound to a porphyrin ring. Google Scholar Cantoni, G.
S-Adenosylhomocysteine is formed when the activated methyl group is transferred to an acceptor. Phosphoglycerate dehydrogenase is regulated by the concentration of serine in the cell.
Google Scholar  The biosynthesis of isoleucine and valine. The wreck blocks the traffic, and the unlucky drivers who got on the highway ahead of the wreck those who got on at E can't get to their destination. This enzyme requires either ammonia or glutamine as the amino group donor.
There are two other negative regulators of cysteine. Carbamyl phosphate, the carbamyl donor in enzymatic citrulline synthesis.