Amino acids are molecules that combine to form proteins. Amino acids and proteins are the building blocks of life.
When proteins are digested or broken down, amino acids are the result. The human body then uses amino acids to make proteins to help the body:
Amino acids can also be used as a source of energy by the body.
Amino acids are classified into three groups:
ESSENTIAL AMINO ACIDS
NONESSENTIAL AMINO ACIDS
Nonessential means that our bodies can produce the amino acid, even if we do not get it from the food we eat. Nonessential amino acids include: alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, and tyrosine.
CONDITIONALLY ESSENTIAL AMINO ACIDS
You do not need to eat essential and nonessential amino acids at every meal, but getting a balance of them over the whole day is important. A diet based on a single plant item will not be adequate, but we no longer worry about pairing proteins (such as beans with rice) at a single meal. Instead we look at the adequacy of the diet overall throughout the day.
Binder HJ, Mansbach CM. Nutrient digestion and absorption. In: Boron WF, Boulpaep EL, eds. Medical Physiology. 3rd ed. Philadelphia, PA: Elsevier; 2017:chap 45.
Dietzen DJ, Willrich MAV. Amino acids, peptides, and proteins. In: Rifai N, Chiu RWK, Young I, Burnham Carey-Ann D, Wittwer CT, eds. Tietz Textbook of Laboratory Medicine. 7th ed. St Louis, MO: Elsevier; 2023:chap 31.
Trumbo P, Schlicker S, Yates AA, Poos M; Food and Nutrition Board of the Institute of Medicine, The National Academies. Dietary reference intakes for energy, carbohydrate, fiber, fat, fatty acids, cholesterol, protein and amino acids. J Am Diet Assoc. 2002;102(11):1621-1630. PMID: 12449285 pubmed.ncbi.nlm.nih.gov/12449285/.BACK TO TOP
Review Date: 1/19/2023
Reviewed By: Stefania Manetti, RD/N, CDCES, RYT200, My Vita Sana LLC - Nourish and heal through food, San Jose, CA. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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