(Ecology 03) Cycles Flashcards
What is the carbon cycle?
The carbon cycle describes how carbon moves between the atmosphere, soils, living creatures, the ocean, and human sources.
What is the water cycle?
The water cycle shows the continuous movement of water within the Earth and atmosphere.
What are nutrient cycles?
The nutrient cycle is a system where energy and matter are transferred between living organisms and non-living parts of the environment.
What are biogeochemical cycles?
A biogeochemical cycle is the movement and transformation of chemical elements and compounds between living organisms, the atmosphere, and the Earth’s crust.
Ex. carbon, water, nitrogen
What is the nitrogen cycle?
The Nitrogen Cycle is a biogeochemical process through which nitrogen is converted into many forms, consecutively passing from the atmosphere to the soil to organism and back into the atmosphere.
How is nitrogen used by organisms?
Nitrogen is an important component of protein and nucleic acids—DNA and RNA.
What are the key processes of the Carbon cycle?
Photosynthesis—Plants and algae take in carbon dioxide and convert itinto sugars using sunlight and water
Cellular respiration—Animals and plants use aerobic cellular respiration to release energy for biological processes. This also releases CO2.
Decomposition—Fungi and bacteria decompose dead organisms & organic waste, releasing organic compounds and CO2.
Fossilization—Under specific conditions, dead organisms can fossilize overthousands & millions of years and can form fossil fuels
Combustion—The burning of fossil fuels is known as combustion. This releases vast amounts of CO2 into the atmosphere.
What are the key processes of the Nitrogen cycle?
Nitrogen fixation—a chemical process that converts atmospheric nitrogen into ammonia, which is absorbed by organisms.
Nitrification—The process by which bacteria in soil and water oxidize ammonia and ammonium ions and form nitrites and nitrates.
Assimilation—This is the uptake of nitrates from the soil by the roots of plants.
Ammonification—In this process, decomposers turn nitrogen compoundsfrom dead organisms and organic waste into ammonium.
Denitrification—the process by which nitrate is reduced to nitrogen gas by soil microbes when oxygen is not present.
How is Carbon used by organisms?
Carbon is known as the element of life. It can form stable bonds with many elements and makes up the backbone of major macromolecules: carbohydrates, proteins, lipids, & nucleic acids.
________ gas makes up 78% of our atmosphere.
Nitrogen
What are the key processes of the water cycle?
Evaporation—When bodies of water are heated by the Sun, water can evaporate, turning to a gas vapor
Transpiration—Water can evaporate from the leaves of plants through tiny holes called stomata.
Condensation—Water vapour condenses when it is cooled, e.g., at higher altitudes, forming clouds in the sky.
Precipitation—When water falls from the sky, we call it precipitation. This includes rain, snow, sleet, and hail.
Percolation—Water moves through soil layers, back to lakes and oceans.Once the soil layer is saturated, it moves as surface runoff.
How does the water cycle work?
- Water would circulate through the environment even without living things.
- Living things return water to the environment through:
*RESPIRATION
*EXCRETION
*TRANSPIRATION
How much freshwater is in the world?
2.5%
Most of it is stored in glaciers, deep underground, or in ice.
Cycles of matter
- Nutrients must be used and reused
- All living things use the same supply of matter over and over again.
- The amount of matter on earth is fixed!
- No more carbon, oxygen, or nitrogen will be added to the Earth!
What are the most important nutrient cycles?
Water, carbon, and nitrogen
Easier way to understand the carbon cycle.
Carbon enters the atmosphere via carbon dioxide.
Carbon dioxide is absorbed and used as energy.
Carbon compounds enter the food chain.
Carbon re-enters the atmosphere via decomposition.
The carbon cycle repeats.
Easy way to understand the water cycle.
Liquid water evaporates into water vapor, condenses to form clouds, and precipitates back to earth in the form of rain and snow.
