Definition of tae kwon do for English Language Learners. : a style of fighting that originated in Korea and that uses kicks and punches but no weapons. Britannica.com: Encyclopedia article about tae kwon do.
It is also used in the baking process as a leavening agent; yeast releasing gas into their environment results in the spongy-like texture of breads and cakes. Because of its role in fermentation, humans have known about and used Saccharomyces cerevisiae for a long time.
Figure 7-23Fermentation in yeast produces ethyl alcohol. The carbon dioxide that isreleased during fermentation creates bubbles and pockets that make breadrise. The alcohol evaporates during baking. There are also fungi and bacteria that produce lactic acid duringfermentation, just as your muscle cells do.Humans use these microbes totransform milk into cheese and yogurt.hen yeast cells are kept in ananaerobic environmentâan environment without oxygenâthey areforced to ferment sugar and other foods. In contrast to fermentation inyour muscle cells, fermentation in yeast produces alcohol, instead oflactic acid, as a waste product (Figure 7-23).