Which of the biochemical processes do yeast perform in order to obtain energy that their cells can use to do work?

Fermentation

Explanation:

Fermentation is a catabolic, anaerobic process, which is not usually accompanied by electronic transport and whose final product is an organic compound. Yeasts are unicellular bodies (generally spherical in shape) with a size of around 2 to 4 μm and that are naturally present in some products such as fruits, cereals and vegetables. They are what are called: facultative anaerobic organisms, that is, they can develop their biological functions without oxygen. Yeasts carry out alcoholic fermentation. Its biological purpose is to provide anaerobic energy to unicellular microorganisms (yeasts) in the absence of oxygen, to dissociate glucose molecules and obtain the energy necessary to survive, producing alcohol and CO2 as fermentation waste.