Here are some websites that discuss the Citric Acid Cycle [Krebs animation][Wikipedia].
This is one of the fundamental biochemical pathways yet both of these sites contain errors. This is the time of the year when I challenge the students in my introductory biochemistry class to find one single website that correctly shows the reactions of the citric acid cycle with all the correct substrates and products (including water and protons). There are two sites that don't count: ones with images from my book (Horton et al.) and ones that are direct copies of the International Biochemistry and Molecular Biology (IUBMB) website. In five years my students have not succeeded. Can any Sandwalk reader find one?
Here are the links to the IUBMB reactions. They all have the correct reaction at some location. You may have to follow one or more of the links to the reaction to see the complete, correct version.
Enzymes of the Citric Acid Cycle
citrate synthase [EC 22.214.171.124]
aconitase [EC 126.96.36.199]
isocitrate dehydrogenase [EC 188.8.131.52][EC 184.108.40.206]
α-ketoglutarate dehydrogenase [EC 220.127.116.11]
succinyl-CoA synthetase [EC 18.104.22.168][EC 22.214.171.124]
succinate dehydrogenase [EC 126.96.36.199]
fumarase [EC 188.8.131.52]
malate dehydrogenase [184.108.40.206]