1. Chemical Cycles Adv Biology 1-2

2. The Carbon Cycle Carbon forms the backbone of all organic compounds. Carbon forms the backbone of all organic compounds. Found in the abiotic part of the environment as carbon dioxide gas. Found in the abiotic part of the environment as carbon dioxide gas.

3. The Carbon Cycle cont’d Producers convert carbon dioxide into sugar during photosynthesis. Producers convert carbon dioxide into sugar during photosynthesis. Consumers get carbon from their food. Consumers get carbon from their food. Carbon is returned to the atmosphere during cellular respiration. Carbon is returned to the atmosphere during cellular respiration. Sugar is broken down to produce ATP. Sugar is broken down to produce ATP. Carbon dioxide is released. Carbon dioxide is released. Done by producers, consumers and most decomposers. Done by producers, consumers and most decomposers.

4. The Carbon Cycle cont’d Some carbon is stored when dead organic matter piles up faster than the decomposers can break it down. Some carbon is stored when dead organic matter piles up faster than the decomposers can break it down. Turned into fossil fuels (coal, oil, natural gas). Turned into fossil fuels (coal, oil, natural gas). Returned to the atmosphere as carbon dioxide when the fuel is burned. Returned to the atmosphere as carbon dioxide when the fuel is burned.

5. The Water Cycle Reactions inside of cells must occur in water. Reactions inside of cells must occur in water. The water cycle is driven by the sun. The water cycle is driven by the sun. Precipitation-rain, sleet, hail, snow, fog. Precipitation-rain, sleet, hail, snow, fog. Occurs when water changes from a gas to a liquid. Occurs when water changes from a gas to a liquid. Evaporation-water changing from a liquid to a gas. Evaporation-water changing from a liquid to a gas. Transpiration-water lost through plants. Transpiration-water lost through plants.

6. The Water Cycle cont’d Water leaves plants and animals when they sweat (evaporation), urinate, transpire (plants) or die. Water leaves plants and animals when they sweat (evaporation), urinate, transpire (plants) or die. Some is stored in glaciers, ice caps or aquifers. Some is stored in glaciers, ice caps or aquifers. Aquifer-underground body of water. Aquifer-underground body of water. The water is returned to the cycle when the ice melts or the aquifer drains. The water is returned to the cycle when the ice melts or the aquifer drains.

7. The Nitrogen Cycle Nitrogen makes up nucleic and amino acids. Nitrogen makes up nucleic and amino acids. Nitrogen gas in the atmosphere is unusable by plants and animals. Nitrogen gas in the atmosphere is unusable by plants and animals. Bacteria in the soil convert nitrogen gas into nitrates. Bacteria in the soil convert nitrogen gas into nitrates. Producers absorb nitrates to make organic compounds. Producers absorb nitrates to make organic compounds. Consumers get N from their food. Consumers get N from their food.

8. The Nitrogen Cycle cont’d Decomposers return nitrogen to the soil. Decomposers return nitrogen to the soil. Break down dead organic matter and put nitrates into the soil. Break down dead organic matter and put nitrates into the soil. Some bacteria convert nitrates into nitrogen gas, returning nitrogen to the atmosphere. Some bacteria convert nitrates into nitrogen gas, returning nitrogen to the atmosphere.

9. The Phosphorus Cycle Phosphorus is used in ATP, proteins, nucleic acids, cell membranes, etc. Phosphorus is used in ATP, proteins, nucleic acids, cell membranes, etc. Most phosphorus is stored in rocks and stones. Most phosphorus is stored in rocks and stones. Weathering releases phosphorus. Weathering releases phosphorus. Weathering-wearing away of rocks by wind, water and lichens. Weathering-wearing away of rocks by wind, water and lichens.

10. The Phosphorus Cycle cont’d Producers absorb phosphate to make organic compounds. Producers absorb phosphate to make organic compounds. Consumers get theirs from their food. Consumers get theirs from their food. Decomposers return phosphorus to the soil. Decomposers return phosphorus to the soil. Increases the amount of phosphorus in the soil. Increases the amount of phosphorus in the soil. Weathering is a very slow process. Weathering is a very slow process.

11. The Phosphorus Cycle cont’d Leaching reduces the amount of nitrogen and phosphorus in the soil. Leaching reduces the amount of nitrogen and phosphorus in the soil. Leaching-removal of chemicals from the soil by water. Leaching-removal of chemicals from the soil by water. Phosphorus in water forms a solid and returns to the earth. Phosphorus in water forms a solid and returns to the earth.

12. N and P as Limiting Factors In most ecosystems, nitrogen and phosphorus are limiting factors. In most ecosystems, nitrogen and phosphorus are limiting factors. Natural processes of creating nitrates and phosphates are slow. Natural processes of creating nitrates and phosphates are slow. Dependent on decomposers to recycle nitrogen and phosphorus. Dependent on decomposers to recycle nitrogen and phosphorus.