What food molecule is broken down during fermentation?

During fermentation, microorganisms break down carbohydrates, which are complex sugar molecules, into simpler compounds, such as ethanol and carbon dioxide. Carbohydrates are the primary food molecules utilized during the process of fermentation. These can be simple sugars, like glucose and fructose, or more complex ones, like starch and cellulose. The type of carbohydrate used will depend on the specific microorganism involved in the fermentation process.