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.
Citric Acid Cycle Steps. 1  Step 1 - The two-carbon acetyl group of acetyl CoA is added to the four-carbon oxaloacetate to form the six-carbon citrate. 2  The conjugate acid of citrate is citric acid, hence the name citric acid cycle. 3  Oxaloacetate is regenerated at the end of the cycle so that the cycle may continue.