![amino acids](https://images.medicinenet.com/images/article/main_image/what-foods-have-amino-acids.jpg?output-quality=75)
Amino acids are the basic building blocks of proteins, the compounds that synthesize hormones and neurotransmitters in our bodies. Amino acids help our bodies to grow, repair body tissue, maintain immunity and produce hormones that maintain body functions.
The 21 amino acids different amino acids our bodies need are:
- Alanine
- Arginine
- Asparagine
- Aspartic acid
- Cysteine
- Glutamic acid
- Glutamine
- Glycine
- Histidine
- Isoleucine
- Leucine
- Lysine
- Methionine
- Phenylalanine
- Proline
- Serine
- Threonine
- Tryptophan
- Tyrosine
- Valine
- Selenocysteine
What are the functions of the 9 essential amino acids?
The 9 essential amino acids play important roles in the body:
- Phenylalanine:
- Produces various chemical messengers (neurotransmitters), such as tyrosine, dopamine, epinephrine and norepinephrine
- Also plays a vital role in the structure and function of proteins and enzymes
- Valine:
- Promotes muscle growth and regeneration
- Also involved in energy production
- Threonine:
- Mostly found in collagen and elastin and a vital component of the skin and connective tissue and helps to:
- Break down fats
- Boost the immune system
- Mostly found in collagen and elastin and a vital component of the skin and connective tissue and helps to:
- Tryptophan:
- Maintains proper nitrogen balance in the body needed for tissue synthesis
- Produces neurotransmitter serotonin that regulates sleep, appetite and mood
- Methionine:
- Promotes tissue growth
- Promotes the absorption of zinc, selenium and other minerals essential for the body
- Leucine:
- Isoleucine:
- Breakdowns muscles
- Produces hemoglobin
- Regulates energy
- Lysine:
- Produces hormones and enzymes
- Helps the body absorb calcium
- Produces energy
- Produces collagen and elastin
- Promotes immune function
- Histidine:
![](https://images.medicinenet.com//images/slideshow/foods-that-arent-as-healthy-as-you-think/foods-that-arent-as-healthy-as-you-think-s1-bulletproof-coffee.jpg)
SLIDESHOW
Foods That Aren't as Healthy as You Think See SlideshowHow are amino acids classified?
Amino acids are classified as essential, nonessential and conditionally essential:
- Essential amino acids: Essential amino acids cannot be made by the body; they must be obtained from the diet.
- Nonessential amino acids: Nonessential amino acids are produced by the body naturally, although they can also be additionally obtained from food. Nonessential amino acids include:
- Alanine
- Arginine
- Asparagine
- Aspartic acid
- Cysteine
- Glutamic acid
- Glutamine
- Glycine
- Proline
- Serine
- Tyrosine
- Conditionally essential amino acids: Conditionally essential amino acids are ones that your body can’t produce under specific circumstances such as stress or illness. Conditional amino acids include:
- Arginine
- Cysteine
- Glutamine
- Tyrosine
- Glycine
- Ornithine
- Proline
- Serine
References
Lopez MJ, Mohiuddin SS. Biochemistry, Essential Amino Acids. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK557845/
Medline Plus. Amino Acids. https://medlineplus.gov/ency/article/002222.htm
Medline Plus. Amino Acids. https://medlineplus.gov/ency/article/002222.htm
Complete List
Top What Are the 21 Amino Acids? Related Articles
10 Foods High in Essential Amino Acids
What are essential amino acids? Learn the best foods for essential amino acids.amino acids/electrolytes/glycerin - injection, Procalamine
amino acids-injection, Aminosyn, Freamine, Travasol
What Are the Benefits and Risks of Taking Amino Acid Supplements?
Learn whether taking amino acids is of a greater benefit or risk to your overall health. Amino acids are building blocks of protein. The amino acids come together to form proteins.Signs You're Not Getting Enough Protein
Are you getting enough protein in your diet? Learn to spot the warning signs of protein deficiency, who is the most at risk, and when you need more protein.Healthy Eating: Veggies That Pack in the Protein
When you think protein, you probably think meat, eggs, and maybe dairy. But veggies have plenty of protein, too. Find out more from WebMD about which ones are the best sources.Healthy Living and Disease Prevention
The importance of a healthy lifestyle in disease prevention is widely understood and most people know that lifestyle changes and choices can be critical to good health. Learn about healthy behaviors that constitute healthy living.High Protein Diets: Good or Bad?
Can a high protein diet help you lose weight fast and help you feel full? High-protein diets are popular, but is there a down side to high protein foods?NephrAmine (essential amino acid)
5.4% NephrAmine (essential amino acid) Injection is amino acids used in conjunction with other measures, to provide nutritional support for uremic patients, particularly when oral nutrition is infeasible or impractical.Prosol (amino acids)
Prosol (amino acids) is indicated as a source of amino acids for patients requiring parenteral nutrition (PN) when oral or enteral nutrition is not possible, insufficient, or contraindicated. Prosol may be used to treat negative nitrogen balance in patients.Protein Quiz
Protein is a staple in our diets, but what happens if we get too much? Take this quiz to find out the truth about protein and what's behind the high-protein diet craze!Should I Take BCAA (Branched-Chain Amino Acids) Everyday?
BCAAs are essential amino acids and should be in your food daily. Without essential amino acids, your body can't keep cellular systems running well.What Are the Nine Essential Amino Acids
What are amino acids? Learn which amino acids are essential to the human body and how you can make sure you’re getting enough.What Do Amino Acids Do?
Amino acids are the building blocks of proteins and play an important role in body functions. They are needed for vital processes like the cell building and synthesis of hormones and neurotransmitters (brain chemicals). They may also be taken as supplements.What Happens When You Eat Too Much Protein?
Our body uses protein to build the muscles and organs, deliver oxygen to the cells, and keep the immune system working. Most people should get at least 10-15% of their daily calories from protein.