What is produced as a byproduct of fermentation in yeast?

The process of fermentation in yeast primarily converts sugars into energy when oxygen is scarce. During this anaerobic process, yeast metabolizes sugars and produces both alcohol and carbon dioxide as byproducts.

Alcohol, specifically ethanol, is produced as a result of the decarboxylation of pyruvate, while carbon dioxide is released from this process as a gas. This dual production is a hallmark of alcoholic fermentation and is particularly significant in industries such as brewing and baking, where both components play a crucial role. In brewing, for instance, ethanol is the desired product, while carbon dioxide contributes to the carbonation of beverages. In baking, carbon dioxide helps dough rise, creating the desired texture in bread.

Understanding that both alcohol and carbon dioxide are products of yeast fermentation highlights its importance in various applications within biotechnology and food production, making "both A and B" the correct response.