Which enzyme catalyses the first reaction of alcohol fermentation, and where in the cell does it work?

1. The first reaction of alcohol fermentation is catalysed by pyruvate decarboxylase. 2. That enzyme is described as a cytoplasmic enzyme, so it works in the cytoplasm. 3. Its coenzyme is thiamine pyrophosphate, derived from vitamin B1. 4. Alcohol dehydrogenase catalyses the second reaction, not the first. 5. Pyruvate dehydrogenase works in the mitochondrial matrix on the aerobic route, so it belongs to a different pathway. 6. Naming a matrix location for any fermentation enzyme is the trap, since fermentation follows glycolysis in the cytoplasm. _Source: OpenStax Biology (1st ed., CC BY 4.0), Ch 7 "Cellular Respiration", section 7.5 Metabolism without Oxygen_