Question
Q9. Anaerobic respiration in yeast is called fermentation. The equation for fermentation is: glucosearrow ethanol+carbondioxide (a) How does the equation show that fermentation is an anaerobic reaction? __ Fermentation in yeast is used in the manufacture of beer, wine and bread. (b) Why is fermentation used when making beer and wine? __
Answer
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Adrian
Elite · Tutor for 8 years
Answer
(a) The fermentation equation does not involve oxygen, either as a reactant or as a product, showing it is an anaerobic process.(b) Fermentation is used when making beer and wine as it produces ethanol, which is the alcohol in these beverages.
Explanation
This question requires knowledge of anaerobic respiration, especially yeast fermentation.(a) The question asks us to explain how the fermentation equation demonstrates fermentation as an anaerobic reaction.Anerobic reactions are reactions that occur in the absence of oxygen. In the fermentation equation in the question, neither the reactants nor the products include oxygen, it's implying it occurs under no oxygen, therefore showing that it's an anaerobic reaction.(b) This part is asking the reason why fermentation is employed in brewing beer and manufacturing wine.The purpose of using fermentation in the process of making beer and wine is primarily to produce ethanol, which is the alcohol present in these beverages. When yeast breaks down glucose in the absence of oxygen, ethanol and carbon dioxide are produced. The ethanol produced inot only imbues these beverages with their alcoholic content, but also contributes to the flavor and the overall profile of the beverages.To extend this idea, during the bread-making process, yeast fermentation produces ethanol and carbon dioxide as well. The carbon dioxide gas helps the dough to rise by creating small bubbles in it. However, the ethanol evaporates during baking.