Methionene, tryptophan, lycine, and isoleucine are four essential amino acids present only in low concentrations in most veggie/nut/legume proteins. That's why

Methionene, tryptophan, lycine, and isoleucine are four essential amino acids present only in low concentrations in most veggie/nut/legume proteins. That's why these proteins are called incomplete. We need them to build and maintain muscle and tissue. I'm sure there are more.