Concept
Amino Acids
Protein-building amino-acid set
Meet the 20 standard amino acids that build most proteins, plus selenocysteine and pyrrolysine, two rare amino acids that some organisms encode directly.
Overview
EXPLORE BY LEVELProteins are built from amino acids linked into chains. The 20 standard amino acids differ in their side chains, which helps determine how a protein folds and works.
Quick Facts
AT A GLANCEStandard set20 amino acids
Rare encoded additionsSelenocysteine and pyrrolysine
What to compareResidue code, side-chain chemistry, and dietary context
Follow the Connections
See how Amino Acids links to other biological records.
All 22 Structured Connections
Recommended Reading
Trusted references for learning more about Amino Acids.
Research Claims
The standard genetic code uses 20 common amino acids, while some organisms also incorporate selenocysteine or pyrrolysine through recoding.