Carbon-Oxygen Cycle
The continuous exchange of carbon and oxygen from non-living environment and to the living.
Aerobic Cellular Respiration
Organisms break down glucose for energy. Oxygen is the input, carbon dioxide output.
Anaerobic Respiration
When oxygen is absent glucose breaks down with a catalyst releasing energy.
Ocean Acidification
When atmospheric carbon reacts with water, forming carbonic acid in the ocean.
How does carbonic acid affect the environment?
It can erode away skeletons and rocks in ecosystems.
Carbon Sinks
Store carbon for a period of time.
Examples of Carbon Sinks
Plants, animals, oceans.
Cellular Respiration
Organisms combine food molecules and oxygen, gives off carbon dioxide. Basically plant breathing.
Water Cycle
The continuous movement of water on and above the Earth’s surface powered by the sun.
Photosynthesis
Plants use the sun’s energy to convert water and carbon dioxide into oxygen and sugars.
Stages of the Water Cycle
Evaporation, condensation, precipitation, infiltration, transpiration, surface run-off.
Evaporation
Liquid to gas, molecules rise into the air in the form of water vapour.
Condensation
Gas to liquid, water cools and forms clouds.
Precipitation
When cloud is fully condensed, water falls in the form of rain, sleet, snow etc.
Infiltration
Water soaks into the ground collecting in layers of rock.
Transpiration
Groundwater is absorbed by plant roots when water evaporates from plants, photosynthesis.
Surface Run-off
Water that cannot soak into the ground, flows across land.
Human Impacts on the Water Cycle
Deforestation: evaporation is disrupted, decreased precipitation, decreased respiration.
Enhanced Greenhouse Effects: Earth’s temperature rises and therefore so does the evaporation rate.
Nitrogen Cycle
The process of how nitrogen changes forms as it is recycled through the biosphere.
Importance of Nitrogen in the Biosphere
It is crucial for forming proteins.
Forms of Oxygen and where they’re found.
Inorganic: Nitrogen gas in the atmosphere. Organic: Wastes & living and dead organisms.
Types of Proteins in the Nitrogen Cycle
Nitrogen fixing
Nitrifying
Denitrifying
Nitrogen Cycle: Nitrogen Fixation
Nitrogen fixing bacteria take up atmospheric nitrogen, converting it to ammonia.
Processes that Fix Nitrogen:
Nitrogen FixationLightning
Nitrogen Cycle: Nitrification
Nitrifying bacteria converts ammonia to nitrite and nitrate ions.
Nitrogen Cycle: Assimilation
Plants absorb ammonium, nitrate, and nitrites.
Nitrogen Cycle: Ammonification
Decomposers return nitrogen to soil by converting compounds in dead organisms to ammonia.
Nitrogen Cycle: Denitrification
Denitrifying bacteria converts nitrates and nitrites to nitrogen gas, releasing it into the atmosphere.
How do animals receive nitrogen?
By feeding on plants that have nitrogen in their roots, they get their nitrogen. Then the food chain continues this process.
Haber-Bosch Process
Synthetic fertilisers where atmospheric nitrogen reacts with hydrogen, turning it to ammonia.
Effects of Nitrogen Fertiliser
Excessive nutrients in water, leading to excessive bacterial growth.
Human Impacts on the Nitrogen Cycle
Burning fossil fuels, nitrogen fertilisers, agriculture.
Eutrophication
Water become excessively enriched with minerals and nutrients.
Algae Blooms
Algae colonies that grow out of control, producing toxic or harmful effects on living organisms.
Phosphorus Cycle
The process of transformation and locations of phosphorus through the hydrosphere, lithosphere and biosphere.
Importance of the Phosphorus in the Biosphere
Required for ATP energy, nucleic acids, cell membranes, and bones.
What is Biogeochemical Cycle does not enter the Atmosphere?
Phosphorus cycle.
Phosphorus Cycle: Weathering
Rocks release phosphate ions and minerals.
Phosphorus Cycle: Assimilation
Plants take inorganic phosphate from soil for use.
Phosphorus Cycle: Decomposition
Dead organisms wastes decompose and organic phosphate is returned to the soil.
Phosphorus Cycle: Mineralisation
Organic forms of phosphate are given to plants via bacteria. This bacteria breaks down organic matter into inorganic phosphate.
Phosphorus Cycle: Sedimentation
Phosphorus can form rocks and end up in sediments.
Human Impact on the Phosphorus Cycle
Mining for phosphorus, relocating it. Altering the distribution of phosphorus.