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step, NADH passes its electrons to acetaldehyde, regenerang NAD and
+
forming ethanol.
Figure 62. Ethanol Fermentaon
Source: https://adapaproject.org/images/biobook_images/eth_fermentation.jpg
Yeasts are good examples of microorganisms that generate ethanol and
CO2 when they carry out fermentaon. When yeasts are used to leaven
bread, the CO2 makes the bread rise. When yeasts are used to ferment
grapes for wine producon, ethanol is the desired product. However, as
the concentraon of ethanol approaches 12%, it becomes toxic to the
yeast. This explains why naturally fermented wine contains only about
12% ethanol.
Learning Tasks and A ssesment
Acvity 1. Differenate anaerobic from aerobic respiraon using the given
criteria.
Criteria Anaerobic respiration Aerobic respiration
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