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yeast
live f

yeast. Yeasts are microscopic organisms that are very beneficial to humans and are used in baking and brewing beer. In this last case, yeasts are used to convert sugars into ethanol:

yeast

C6H12O6 → 2C2H5OH + 2CO2

(aqueous) glucose > yeast > (aqueous) ethanol + (gas) carbon dioxide

This reaction produces alcoholic beverages such as beer and wine. Carbon dioxide may be collected and sold or allowed to escape into the atmosphere.
In the case of baking, carbon dioxide is useful, as the dough is mixed and then the sugar and yeast react in it to produce the gas. The gas makes the dough expand (puff) and the mixture becomes much lighter. Yeasts contain enzymes, which are substances that react with sugars. See zymase.


yield of reaction
rendement m de reaction

The outcome of the interaction. There are many chemical reactions that do not produce as many products as expected from looking at chemical equations. It is usual to express the quantity of output as a percentage of what could theoretically be produced:

Reaction yield = actual amount of product / maximum amount of product that can be produced

Example :
CuO (solid) + H₂ (gas) → Cu (solid) + H₂O
Water - copper - hydrogen - copper (II) oxide

(Maximum yield) 64 g → 80 g

If 80 grams of oxides actually produce 56 grams of copper metal, the reaction yield percentage is: 87.5% = % (56/64 x 100)