Six astronauts are still on the space station as part of a planned year-long stay in space, the longest tour of duty in the station's 15-year history.
The molecular formula of citric acid is C 6 H 8 O 7. The chemical formula for citric acid is best shown by a diagram of its complete structural formula. This shows how the atoms are arranged in the molecule. Citric acid has three carboxyl or-COOH groups and is triprotic in nature.
Principles of Biochemistry/Krebs cycle or Citric acid cycle - Enzymes in Citric acid cycle pathway. 1  The enzyme citrate synthase (E.C. 2.3.3.1 [previously 4.1.3.7]) exists in nearly all living cells and stands as a pace-making enzyme in the first step of the Citric Acid Cycle (or Krebs Cycle). 2  Oxaloacetic acid. 3  Citric acid.