nutrient
Isoleucine
A branched-chain essential amino acid used in proteins and energy metabolism.
Isoleucine has a branched hydrocarbon side chain and a carbon portion that enters central metabolism after amino-group removal.
One member of a three-amino-acid group
Isoleucine is one of the three branched-chain amino acids. Its branch structure groups it with leucine and valine, while its carbon route remains distinct.
Related topics
Isoleucine is used to build Protein
Isoleucine is one of the amino acids used to assemble proteins.
Worth knowing
It is dietarily essential. Isoleucine is one of nine amino acids humans must obtain from food.
A closer look
BCAA members have distinct pathways
Leucine, isoleucine and valine share a branched side chain but differ in their carbon-skeleton pathways.
Carbon fate is specific
Isoleucine can contribute to both glucogenic and ketogenic metabolic products after catabolism.
References
Source-checked local draft.
Human editorial review pending.
- NIH National Library of MedicineBiochemistry, Essential Amino AcidsChecked 2026-09-05
- NIH National Library of MedicineBiochemistry, Protein CatabolismChecked 2026-09-05