Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Cycles of Materials In a self-sustaining ecosystem, various materials are recycled between organisms and the abiotic environment. The recycling process allows materials to be used over and over again. Three major cycles are: 1. Carbon-hydrogen-oxygen cycle 2. Water cycle 3. Nitrogen cycle Mrs. Degl 1 Carbon-hydrogen-oxygen cycle Mrs. Degl 2 Carbon-hydrogen-oxygen cycle Carbon, hydrogen, and oxygen are recycled through the environment by the processes of respiration and photosynthesis. Mrs. Degl 3 Water Cycle Mrs. Degl 4 Nitrogen Cycle Mrs. Degl 5 Nitrogen Cycle Nitrogen is needed by all living things because it is part of the structure of amino acids and proteins. In this cycle, nitrogenous wastes and the remains of dead organisms are converted by decomposers and soil bacteria into compounds that can be used by autotrophs. The Nitrogen cycle includes the following reactions: 1. Atmospheric nitrogen is converted into nitrates by the nitrogen-fixing bacteria. 2. Nitrates are used by plants for the synthesis of proteins. 3. Animals feed on plants and convert plant proteins to animal proteins . Mrs. Degl 6 4. Nitrogenous wastes and dead organisms are decomposed and ammonia is released. 5. Ammonia is converted to nitrates by nitrifying bacteria. 6. Denitrifying bacteria break down nitrogen compounds and release nitrogen gas into the atmosphere. Mrs. Degl 7