CTET Paper II (Mathematics and Science) Dec 2018 Solved Paper

Concept:Yeast performs anaerobic fermentation, converting sugars into ethanol (alcohol) and carbon dioxide.Explanation:Yeast breaks down glucose into pyruvic acid under oxygen‑free conditions.Then, pyruvic acid is decarboxylated to acetaldehyde, which is reduced to ethanol using the enzyme alcohol dehydrogenase.This process is known as fermentation.The overall reaction: $C_{6}H_{12}O_{6} \rightarrow 2 C_{2}H_{5}OH + 2 CO_{2}$.Hence, yeast is specifically used for alcohol production, not for curd, sugar, or common salt.Answer:A. alcohol