1. Anaerobic Respiration:
* Yeast are facultative anaerobes, meaning they can survive with or without oxygen.
* In the absence of oxygen, yeast utilize fermentation to generate energy.
2. Sugar Breakdown:
* Yeast consume sugars (like glucose) as their food source.
* They break down these sugars through a series of enzymatic reactions called glycolysis.
3. Pyruvate Conversion:
* Glycolysis produces pyruvate.
* In fermentation, pyruvate is converted into ethanol (alcohol) and carbon dioxide.
4. Carbon Dioxide Release:
* The carbon dioxide produced during fermentation is released as a gas, causing the characteristic bubbles in beer, wine, and bread.
Overall Equation:
The overall equation for alcoholic fermentation is:
C6H12O6 → 2 C2H5OH + 2 CO2
This means that one molecule of glucose is broken down into two molecules of ethanol and two molecules of carbon dioxide.
In summary, yeast produces carbon dioxide through fermentation, a process where they break down sugars in the absence of oxygen to generate energy and release carbon dioxide as a byproduct.
