Definition of "tryptophan" [tryptophan]

• An essential amino acid, C11H12N2O2, formed from proteins during digestion by the action of proteolytic enzymes. It is necessary for normal growth and development and is the precursor of several substances, including serotonin and niacin. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "In plants, the tryptophan is produced endogenously where in animals the tryptophan used comes from diet."
• "This is because bananas contain tryptophan, a type of protein that the body converts into serotonin, known to make you relax, improve your mood and generally make you feel happier."
• "To make matters more interesting, tryptophan is present in many protein-rich foods, which have been found to prevent serotonin production."