Biogeochemical Cycles
Biogeochemical Cycles Essential Knowledge Objectives 2.A.3 (a) Biogeochemical Cycles • Cycle inorganic and organic nutrients between organisms and the environment – Carbon cycle – Nitrogen cycle – Phosphorus cycle – Water cycle (also known as the hydrological cycle) Cycling of Matter • Organisms must exchange matter with the environment to grow, reproduce and maintain organization • Molecules and atoms from the environment are necessary to build new molecules Molecules Essential for Life • Carbohydrates – composed of C, H, and O, monomer is a monosaccharide • Lipids – composed of C, H, and O, monomers are fatty acids and glycerol • Proteins – composed of C, H, O, N, and S in trace amounts, monomers are amino acids • Nucleic Acids – composed of C, H, O, N and P, monomers are nucleotides Carbon • Carbon moves from the environment to organisms where it is used to build the essential organic molecules • Carbon is used in storage compounds and cell formation in all organisms Carbon in the Environment • Carbon found in something non-living is called inorganic carbon • Inorganic carbon is found in rocks (limestone), shells, the atmosphere and the oceans • Living organisms must “fix” inorganic carbon into organic carbon to build the organic compounds necessary for life Carbon Cycle Nitrogen and Phosphorus • Nitrogen moves from the environment to organisms where it is used to build proteins and nucleic acids • Phosphorus moves from the environment to organisms where it is used to build nucleic acids, certain lipids, and ATP (cell energy) Nitrogen
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