Final answer:
C. Fermentation
Fermentation is the biochemical process where yeast or bacteria convert carbohydrates into carbon dioxide, acids, and alcohol; the correct answer is C. Fermentation. Ethanol and CO2 are the main byproducts of this process, critical to making alcoholic beverages and bread rise.
Step-by-step explanation:
Fermentation is the process of converting carbohydrates to carbon dioxide, acids, and alcohol by yeast or bacteria. The correct answer to the student's question is C. Fermentation. This biochemical process enables yeast cells to live in the absence of oxygen. In the context of alcohol fermentation, primarily done by the yeast Saccharomyces cerevisiae, fermentation involves the conversion of sugars such as glucose (C6H12O6) to ethanol (C2H5OH) and carbon dioxide (CO2). The balanced chemical reaction for the fermentation of glucose is:
C6H12O6 → 2C2H5OH + 2CO2
The first step in this fermentation process is catalyzed by pyruvate decarboxylase, which removes a carboxyl group from pyruvate, forming acetaldehyde and releasing CO2. The second step is catalyzed by alcohol dehydrogenase, which reduces acetaldehyde to ethanol while oxidizing NADH to NAD+. This reaction is essential for the production of alcoholic beverages and is also responsible for making bread rise due to the CO2 produced. Moreover, it plays a significant role in producing biofuels from plant products.