CYCLING & RECYCLING OF MATTER 2.1 FYI Life has 5 major requirements Energy, Water, Inorganic Carbon, Oxygen, & Nutrients Oxygen and nutrients are generally combined with carbon and oxygen. We call these mixtures organic compounds. The Importance of Cycling Because our biosphere contains a limited (or finite) number of atoms, new compounds can only be formed from atoms that are released during cycling. It is essential that matter be recycled to help balance our biosphere and maintain life on earth. The cycling of organic compounds happens in 2 ways Eating and digestion Decay and decomposition Important elements and compounds C carbon is a component of organic molecules of which all organisms are composed CO 2 carbon dioxide is necessary for photosynthesis which is needed to begin the food chains and food webs O 2 oxygen (gas) is necessary for most living things H 2 O water is necessary for all organisms C 6 H 12 O 6 sugar (glucose) is a form of food storage in plants and a source of energy of organisms N nitrogen is a component of proteins and nucleic acids (DNA; Chromosomes) N 2 gaseous nitrogen is the most abundant gas found in the air Important elements and compounds Homework NOW! Page 51: 1, 2, 4, 5 NO 3 nitrate is a useable form of nitrogen; often formed by bacteria in the soil and on roots P phosphorous is found in energy storage called ATP; also found in nucleic acids PO 4 phosphate is a common form of phosphorous found in rocks, soil, limestone etc