Unit 1 Outcome 1 Flashcards
(95 cards)
Carbon-oxygen cycle
The biogeochemical cycle by which carbon is exchanged among the Earth’s spheres
Limestone weathering (carbon-oxygen)
Calcium carbonate in limestone reacts with acids in rain and soil, producing carbon dioxide which moves into the atmosphere
Fossilisation and unavailable carbon (carbon-oxygen)
Involves burial and transformation of organic matter into fossil fuels (coal, oil, natural gas). Removes carbon from cycle to store as unavailable carbon
Combustion of fossil fuels (carbon-oxygen)
Carbon dioxide is released into the atmosphere when fossil fuels are burned. Human impact on carbon cycle.
Deforestation and fires (carbon-oxygen)
When trees and vegetation are cut down, burned or left to decay, the carbon stored in their biomass is released into the atmosphere as CO2
Photosynthesis (carbon-oxygen)
Plants absorb solar energy, carbon dioxide and water to convert them into oxygen, water and glucose (energy)
Cellular respiration (carbon-oxygen)
Animals eat the glucose-containing plants to power cellular respiration, and then release CO2 as a waste product
Decomposition (carbon-oxygen)
Decomposers break down complex organic molecules into simpler compounds (such as CO2) through the process of decay
Carbon sequestration (carbon-oxygen)
Plants or oceans absorb carbon dioxide. Removing carbon from atmosphere.
Volcanic eruption (carbon-oxygen)
Release large amount of carbon dioxide directly into atmosphere
Nitrogen cycle
The nitrogen cycle transforms and circulates nitrogen in various forms through Earth’s spheres
Atmospheric nitrogen fixation (nitrogen)
Lightning strike generates energy which splits nitrogen gas into nitric oxide and nitrogen dioxide. These then dissolve in water droplets in clouds, which is them transported to Earth’s surface through precipitation.
Assimilation (nitrogen)
Plants and some microorganisms take up ammonium and nitrate ions from the soil
Consumption (nitrogen)
Animals acquire organic nitrogen by consuming plants or other animals
Ammonification (nitrogen)
Decomposers break down organic nitrogen compounds found in dead organisms, faeces, and other organic matter to convert them to ammonia or ammonium ions to release them back into the soil.
Volcanic eruptions (nitrogen)
Volcanic eruptions release nitrogen gas straight into the atmosphere
Denitrification by bacteria (nitrogen)
Denitrifying bacteria convert nitrate and nitrite ions into nitrogen gas. Opposite to nitrification.
Nitrogen fixation by bacteria (nitrogen)
Atmospheric nitrogen gas is converted into ammonia or ammonium ions by nitrogen-fixing bacteria found in the soil
Nitrification (nitrogen)
Ammonia is converted to nitrite ions by nitrifying bacteria. Nitrite ions are oxidized into nitrate ions by other nitrifying bacteria.
Water cycle
The continuous cycling and exchange of water on, above, and below the Earth’s surface. Driven by solar energy.
Transpiration (water)
Water is absorbed by plants from the soil through their roots. Water is pulled up the stem by transpirational pull and is evaporated from leaves into the atmosphere.
Condensation (water)
When in the atmosphere, water vapour cools and condenses, it forms clouds
Precipitation (water)
Occurs when clouds become saturated with water droplets which then fall to the ground
Surface run-off (water)
The movement of water over the land surface. Run-off then collects in bodies of water.