1. Carbon Cycle

2. Nutrient Cycles in Ecosystems— Biogeochemical Cycles Organisms are composed of molecules and atoms that are cycled between living and non- living portions of an ecosystem. These nutrient cycles are called biogeochemical cycles.

3. Carbon Cycle 1.Carbon and oxygen combine to form carbon dioxide. 2.Plants use carbon dioxide during photosynthesis to produce sugars. 3.Plants use sugars for plant growth. 4.Herbivores eat plants, break down the complex organic molecules into simpler molecular building blocks, and incorporate those molecules into their structure. 5.Respiration breaks down organic molecules into CO 2 and water and releases those compounds back into the atmosphere.

4. Carbon Cycle 6.The decay process of decomposers involves respiration and therefore recycles naturally occurring organic molecules. 7.Burning fossil fuels takes carbon atoms that were removed temporarily from the active, short-term carbon cycle and reintroduces them into the active cycle.

5. Carbon Cycle Carbon cycle