Biogeochemical Cycles T^T Flashcards
What is the Water Cycle?
Water vapor is created by the sun causing evaporation of bodies of water such as oceans and lakes; water vapor is carried by the winds to almost the whole world; and condenses in the air to make rain or snow (precipitation); then is returned to the land or ocean; eventually the water that lands on land makes its way to plants or rivers and streams that lead back to the oceans; plants take in the water and use it for photosynthesis but also can lose it in the form of transpiration to the air
What is the Carbon Cycle?
Carbon dioxide (CO2) is removed from the air by photosynthesizing organisms such as plants etc; these sugars, which contain carbon are then passed from organism to organism through the food chain; all organisms then release the carbon in the form of CO2 by performing the process of cellular respiration in their cells; the burning of plant materials, natural gas, and fossil fuels, which are the remains of dead life forms such as dinosaurs and pre-historic forests, puts carbon dioxide back into the air as well
What is the Nitrogen Cycle?
The majority of nitrogen is removed from the air by water; this happens because water is a universal solvent so the gas is dissolved in the rain or snow; The nitrogen in the water is mainly consumed by nitrogen-fixing bacteria, in the soil, then converted it into ammonium, this is referred to as Nitrogen Fixation; ammonium can then be absorbed by plants to help make proteins and DNA or RNA; some ammonium in the soil is also consumed by nitrifying bacteria and converted to nitrite and then into nitrate, this is referred to as nitrification; nitrates are also absorbed by the plants, just as was the ammonium; some other bacteria in the soil can also eat the nitrates, these are called denitrifying bacteria, the consume the nitrates and break it down into oxygen gas and nitrogen gas and both are returned to the air to be used again, this process is called denitrification; As animals eat plants the nitrogen travels through the food chain when all life forms die, the bodies decompose and create ammonia which is why they stink; the ammonia is converted by bacteria into ammonium and is used again by plants and bacteria, the conversion is called ammonification
What is the Phosphorus Cycle?
Phosphorus is initially a component of rock; as the rock breaks down over time, weathering, the phosphorus is released into the soil; some dissolve into the water as the rain passes through the soil; phosphorus makes its way into bodies of water, such as lakes and oceans, and is available for producers (phytoplankton) to use to help make organic compounds such as phospholipids and DNA and RNA; plants can also retrieve the phosphorus from the soil and use ti to make organic compounds too when organisms die, decomposers break down the bodies and return the phosphorus back to the soil to be reused.
