Glutamine
Glutamine is the most abundant naturally occurring, nonessential amino acid in the human body, and one of the few amino acids that can directly cross the blood–brain barrier. Humans obtain glutamine through catabolism of proteins in foods they eat. In states where tissue is being built or repaired, like growth of babies, or healing from wounds or severe illness, glutamine becomes conditionally essential.
Complete protein
It was once thought that plant sources of protein are deficient in one or more amino acids, and so vegetarian diets had to specifically combine foods during meals, which would create a complete protein. However, the most recent position of the Academy of Nutrition and Dietetics is that protein from a variety of plant foods eaten during the course of a day supplies enough essential amino acids when caloric requirements are met. Normal physiological functioning of the body is possible if one obtains enough protein and sufficient amounts of each amino acid from a plant-based diet. In fact, the highest PDCAAS scores are not given to commonly eaten meat products, but rather to animal-derived vegetarian foods like milk and eggs and the vegan food soy protein isolate.