IGCSE Biology glossary
Ethanol
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Definition
One of the products of anaerobic respiration in yeast and some plant cells. The equation for anaerobic respiration in yeast is: glucose produces ethanol plus carbon dioxide. This process is used in brewing and baking.
What to include in an exam answer
Anaerobic respiration in yeast produces ethanol AND carbon dioxide. In animals it produces lactic acid (not ethanol). This difference is a classic exam comparison.
Example in context
Compare the products of anaerobic respiration in yeast and in human muscle cells (2 marks): In yeast, anaerobic respiration produces ethanol and carbon dioxide. In human muscle cells, it produces lactic acid only.
Related syllabus topic
Respiration