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:
- 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:
- Promotes muscle repair
- Regulate blood sugar levels
- Stimulates wound healing
- Produces growth hormones
- 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:
- Used to produce neurotransmitter histamine, which controls:
- Immune response
- Digestion
- Sexual function
- Sleep-wake cycles
- Used to produce neurotransmitter histamine, which controls:
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
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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
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