What is the end product of fermentation in yeast?

The end product of fermentation in yeast is ethanol. During the process of fermentation, yeast converts sugars such as glucose into ethanol and carbon dioxide in the absence of oxygen. This anaerobic respiration allows yeast to generate energy when oxygen levels are low. The production of ethanol is significant, particularly in the context of brewing and baking, where the release of carbon dioxide helps bread rise and the ethanol contributes to the alcoholic content in beverages.

In contrast, acetic acid is typically a product of fermentation by certain bacteria, while lactic acid is produced during anaerobic respiration in other organisms, such as muscle cells in animals. Glucose, being a substrate for fermentation, is consumed during the process rather than produced. Thus, the primary end product of fermentation in yeast is indeed ethanol.