What metabolic process do yeast use to produce carbon dioxide?

Yeast predominantly utilize fermentation to produce carbon dioxide, particularly in the absence of oxygen. During fermentation, yeast converts sugars into alcohol and carbon dioxide through a series of metabolic pathways. This process is essential for aerobic conditions and is commonly exploited in the production of beverages like beer and bread, where the carbon dioxide produced causes dough to rise or provides carbonation in beer.

While anaerobic respiration can produce energy without oxygen, in the context of yeast, fermentation specifically refers to the conversion of sugars into alcohol and carbon dioxide, thus making it the more accurate term to describe the metabolic process at work when producing carbon dioxide in this setting. Other processes such as aerobic respiration involve the presence of oxygen to produce energy and do not directly focus on carbon dioxide production in the same way yeast fermentation does. Photosynthesis, on the other hand, is a process used by plants to convert light energy into chemical energy and does not apply to yeast, which do not perform photosynthesis.