In Yeast, the pyruvate is decarboxylated to form----

In yeast, during anaerobic respiration (alcoholic fermentation), pyruvic acid undergoes incomplete oxidation in two steps.

First, pyruvic acid is decarboxylated to form acetaldehyde and carbon dioxide. This reaction is catalyzed by the enzyme pyruvate decarboxylase.

Second, acetaldehyde is reduced to ethyl alcohol (ethanol) by the enzyme alcohol dehydrogenase, utilizing NADH + H^{+}$.<br><br>Therefore, the direct product of the decarboxylation of pyruvate is acetaldehyde.<br><br>Answer: Acetaldehyde$