Biogeochemical Cycles Honors Biology

Recall Energy FLOWS through ecosystems ◦Sun  Chemical Energy  Usable Energy  Heat (glucose, food) (ATP) Energy is never created nor destroyed, but can change forms ◦Law of thermodynamics

Matter in Ecosystems Matter is conserved in chemical reactions ◦Not created nor destroyed but can be changed ◦Conservation of matter

Earth’s Spheres Atmosphere ◦Gases that surround Earth Hydrosphere ◦All water on Earth Geosphere/Lithosphere ◦Solid Earth Biosphere ◦All life on Earth

What happens in one sphere effects the others

Biogeochemical Cycles Bio = life ◦Geo = Earth  Chemical = processes ◦ Cycles = series of repeated events Responsible for the cycling of matter in ecosystems, essential to life Responsible for the cycling of matter in ecosystems, essential to life 4 cycles: ◦Phosphorus ◦Water ◦Nitrogen ◦Carbon**

Phosphorus Cycle Phosphorus is needed for nucleic acids, ATP, cell membranes

Water Cycle Water is essential to the metabolism of all organisms

Nitrogen Cycle Nitrogen is part of amino acids, proteins and nucleic acids

Carbon Cycle Carbon forms the the framework of all molecules essential to life Key processes: ◦Photosynthesis  Plants use CO 2 for photosynthesis, make glucose and O 2 ◦Cellular respiration  All organisms use glucose and O 2 to make ATP, release CO 2 ◦Human impact!  Activities increase in CO 2 atmosphere  Removing plants means CO 2 isn’t being cycled as quickly as it is being added  Greenhouse effect and global climate change