Lactic acid fermentation
Lactic acid fermentation is common in muscle cells that have run out of oxygen.
Source
Boundless vets and curates high-quality, openly licensed content from around the Internet. This particular resource used the following sources:
"OpenStax College, Metabolism Without Oxygen. October 16, 2013."
http://cnx.org/content/m44444/latest/Figure_07_05_02.png
OpenStax CNX
CC BY 3.0.
