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.
All beer leaves the brewer carbonated. This is accomplished in one of two ways - natural and forced carbonation. In both cases, beer and carbon dioxide are sealed in a container under pressure. The beer absorbs the CO2 giving the beer its fizz. Natural carbonation results from the fermentation process. Fermentation produces alcohol and carbon dioxide as yeast digests the sugar in the wort. Although most of the carbon dioxide is allowed to escape during fermentation the brewer will seal the beer in a container when it is almost complete. This is how natural carbonation is used to carbonate beer in holding vessels at the brewery and in casks. Anther way to use natural carbonation is in the bottle.