I believe it is either fish of plants (Most likely plants).
Acid-laden ingesta flows out of the stomach, into the small intestine. Acid in the small intestine stimulates secretion of the hormone secretin<span> from endocrine cells in the intestinal epithelium.</span>
Humans get amino acids from protiens in the food we eat. As we digest the food, the enzymes in our stomach and small intestines break down proteins into small amino acids. So technically, we do not make amino acids, we get amino acids from eating food high in protiens.
