Cambridge O Level Biology · Syllabus 5090 · Biotechnology and Genetic Modification
Yeast in ethanol production
What is Yeast in ethanol production?
The use of yeast to make ethanol on an industrial scale. A sugar source such as grain or fruit is prepared as a solution and yeast is added to a closed vessel, so that oxygen is limited or excluded and the yeast respires anaerobically. Glucose is converted to ethanol and carbon dioxide; the carbon dioxide escapes through a gas outlet while the ethanol accumulates in the liquid and is collected. Temperature and pH are held near suitable values throughout so that the yeast's enzymes work efficiently without denaturing. The ethanol produced may be used for beverages, for industrial purposes or as a biofuel.
This definition is part of the Biotechnology and Genetic Modification chapter in Cambridge O Level Biology.