Question

During alcoholic fermentation, oxygen is not present. The pyruvic acid from glycolysis is broken down to produce __________ and carbon dioxide instead of lactic acid. A. citric acid B. alcohol C. yeast D. oxygen

Answer 1

Yeasts and a few other microorganisms use alcoholic fermentation, whichh produces ethyl alcohol and carbon dioxide.
Alcoholic fermentation after glycolysis is
Pyruvic acid+NADH--->Alcohol+CO 2+NAD+

When yeast cells in the dough run out of oxygen, the dough begins to ferment, giving off tiny bubbles of carbon dioxide. These bubbles form the air spaces you see in a slice of bread. The small amount of alcohol produced in the dough evaporates when the bread is baked.

Unlike alcoholic fermentation, lactice fermentation does not give off carbon dioxide. However, like alcoholic fermentation, lactice acid fermentation also regenerates NAD+ so that glysolysis can containue.
Lactic acid fermentation after glycolysis can be summarized as
Pyruvic acid+NADH-->Lactic acid+NAD+
Humans are lactic acid fermenters. During brief periods without oxygen many of the cells in our bodies are capable of producing ATP by lactic acid fermentation. The cells best adapted to doing that, however, are muscle cells, which often need very large supplies of ATP for rapid bursts of activity.
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