Fermentation

In the syllabus and the exam

Fermentation is presented as the everyday, applied face of anaerobic respiration in yeast and certain bacteria, linking pure biology to food technology contexts such as bread-making, brewing and yoghurt production. SPM questions frequently describe an industrial or kitchen scenario and ask candidates to write the word equation for fermentation, identify the gas responsible for dough rising or drink fizziness, and explain why fermentation vessels are sometimes sealed to exclude oxygen. Candidates must distinguish fermentation in yeast, which yields ethanol and carbon dioxide, from anaerobic respiration in human muscle, which yields lactic acid instead; using the two terms interchangeably across organisms is a common error that costs marks. Another expected skill is linking fermentation to biotechnology, since the same anaerobic pathway in yeast is exploited to produce alcoholic beverages and to leaven baked goods, giving the concept relevance beyond the respiration chapter alone.

Example

Bakers rely on fermentation in yeast to release carbon dioxide that makes bread dough rise before baking.

Related terms

Anaerobic respirationATPBiotechnology

Source:SRC-DSKP-EN