Final answer:
Single-celled yeast, specifically Saccharomyces cerevisiae, is used in bread making for alcoholic fermentation, turning sugars into ethanol and carbon dioxide, which helps bread rise and contributes to its texture and flavor.
Step-by-step explanation:
The single-celled organisms that use the fermentation process in bread making are yeasts, specifically a species known as Saccharomyces cerevisiae, also referred to as brewer's or baker's yeast. These organisms perform alcoholic fermentation in the absence of oxygen, converting sugars such as glucose into ethanol (CH3CH2OH) and carbon dioxide (CO2). This process not only causes bread to rise, due to the production of carbon dioxide, but also contributes to the flavor and texture of the bread. The alcohol produced during fermentation evaporates during baking.
Saccharomyces cerevisiae is not only pivotal in the production of bread but also plays a significant role in making wine and beer. These yeasts are ideal for fermentation because they are easy to culture, grow rapidly, and their behavior during fermentation is predictable. Additionally, Saccharomyces cerevisiae has been instrumental in scientific research, serving as a model organism in genetics and cellular biology.