Final answer:
Pyruvate decarboxylase catalyzes the decarboxylation of pyruvate, forming carbon dioxide and acetaldehyde, using thiamine pyrophosphate as a coenzyme. This process is vital to the production of ethanol during yeast fermentation.
Step-by-step explanation:
Pyruvate decarboxylase catalyzes the removal of a carboxyl group from pyruvate, producing carbon dioxide and acetaldehyde. This enzyme, which operates in the cytoplasm, uses the coenzyme thiamine pyrophosphate (TPP), derived from vitamin B1. As pyruvate undergoes decarboxylation, carbon dioxide is released as a gas and the molecular size is reduced, with the resultant two-carbon molecule being acetaldehyde. This process is integral to the fermentation of pyruvic acid by yeast, whereby ethanol is produced, commonly found in alcoholic beverages. The reaction is considered oxidatively decarboxylated since a redox reaction is involved where NAD+ is reduced to NADH.