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.
Yeast is a single-celled organism and only certain strains are used for fermenting grain. Yeast activation and the initiation of fermentation are triggered by hydration, from either water or some other liquid, and the presence of a food source. Fermentation ends at 140 degree F during baking when heat kills the yeast.