4.) metal
"-the movement of carbon from the nonliving environment into living things and back to the environment
-carbon is the essential component of proteins, fats, and carbohydrates (which make up all organisms)
-carbon exists in air, water, and living organisms
-producers convert carbon dioxide in the atmosphere into carbohydrates during photosynthesis
-bacteria in the atmosphere cycles through the system in filtration units
-in cellular respiration, carbon is released back into the atmosphere as carbon dioxide
-some carbon is stored in limestone (forming one of the largest "carbon sinks" on earth)
-largest carbon reservoir on earth= limestone
-carbon stored in the bodies of organisms as fat, oils, or other molecules may be released into the soil or air when the organism dies
-this may form deposits of coal, oil, or natural gas (fossil fuels, which increased the atmospheric carbon dioxide)
-fossil fuels store carbon left over from bodies of organisms that died millions of years ago
-they are located in the surface of earth, deep within the earth and beneath the ocean floor."
