Tricarboxylic acid

A tricarboxylic acid is an organic carboxylic acid whose chemical structure contains three carboxyl functional groups (−COOH). The best-known example of a tricarboxylic acid is citric acid.

Citric acid cycle
Citric acid, a type of tricarboxylic acid, is used in the citric acid cycle – also known as tricarboxylic acid (TCA) cycle or Krebs cycle – which is fundamental to all aerobic organisms.