A 40 year old manager experiences abdominal pain post lunch. He goes to the restroom a couple of times, but continues to experience pain and cramps. He had consumed two bottles of beer at lunch. The alcohol (ethyl alcohol/ethanol) content in a bottle of beer is about 5%. The man's weight is 150 lbs. and he was drinking over an hour period. What was the chemical reaction in the body, and what substance in the liver was produced to help catalyze the reaction?