Most centipedes need to live in moist places, but a few can survive in deserts and dry grasslands. 1  These animals are found in the following types of habitat. 2  temperate. 3  tropical. terrestrial.  Terrestrial 1  Biomes. taiga.  desert or 1  dune. chaparral. 2  forest. rainforest. 3  scrub forest.  mountains.
Yeast are among the few living organisms that do not need oxygen in order to produce energy. This oxygen-independent state is called anaerobic (pronounced a-na-ROE-bik; without oxygen). During such anaerobic conditions, yeast convert carbohydratesâstarches and sugarsâto alcohol and carbon dioxide gas. This process is known as fermentation. The fermentation process of yeast is caused by enzymes, catalysts in chemical reactions similar to the digestive enzymes in the human body.
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).