Chapter 4 - Carbon Cycle Flashcards
What is the current carbon dioxide concentration of the atmosphere at the moment?
0.039%
And aquatic habitats How is carbon dioxide present?
As a dissolved gas and hydrogen carbonate ions
What is absorbed by aquatic plants and other autotrophs that live in water?
Dissolved co2 and hydrogen carbonate ions
How does carbon dioxide diffuse from the atmosphere?
Because autotrophs use carbon dioxide in the production of carbon compounds by photosynthesis
What is produced by respiration?
Carbon dioxide and diffuses out of organisms into water or the atmosphere
What is co2 a waste product of?
Aerobic cell respiration
Co2 is a waste product of aerobic cell respiration- it is produced in all cels that carry out this respiration - what are the 3 groups that do it?
1) non-photosynthetic cells in producers for example root cells in plants
2) animal cells
3) saprotrophs such as fungi that decompose dead organic matter
What is methane produced from?
Methane is produced from organic matter in anaerobic conditions By methanogenic archaens and some diffuse into the atmosphere
What are the 3 groups of anaerobic prokararyotes that have methane as a waste product?
1) bacteria that convert organic matter
2) bacteria that use the organic acids and alcohol
3) archaens that produce methane from 2 different chemical reactions
Where do archaea a that are methanogenic carry out methanogenesis ? (4)
1) mud along shores
2) swamps, wetlands etc
3) guts of termites
4) landfill sites where organic matter is in wastes that have been buried
What is methane oxidised to?
Carbon dioxide and water in the atmosphere
Why are atmopheric conditions not high in methane?
Molecules of methane released into the atmosphere only last there on average for 12 years
Why does peat form?
When organic matter is not fully decomposed because of anaerobic conditions in waterlogged soils
Why is organic matter sometimes not fully deoxmposed
In some environments water is unable to drain out of soils so they become water logged and anaerobic (saprotrophs thrive in aerobic conditions) - so cannot thrive and acidic conditions tend to develop
Carbon and some compounds of carbon are chemically very stable and can remain unchanged in rocks for hundreds of years - where are they kept?
There are large deposits - result of incomplete decomposition of organic matter and its burial in sediments that become rock
How is coal formed?
When deposits of peat are buried under other sediments- pears are compressed and heated, gradually turning to coal
How is oil and natural gas formed?
In the mud at the bottom of seas and lakes - conditions are usually anaerobic and so decomposition is often incomplete - as more mud and other sediments are deposited all becomes compressed and heated- chemical changes occur, which produces complex mixtures of liquid carbon compounds or gases
What is a way of carbon dioxide being produced?
By the combustion of biomass and fossilised organic matter
What is combustion
Organic matter is heated to its ignition temperature in the presence of oxygen = combustion
What are the products of complete combustion?
Carbon dioxide and water
What are the three forms of fossilised organic matter?
Coal, oil and natural gases - all burned as fuels
What type of animals can become fossilised and why?
Reef-building corals and molluscs have hard parts that are composed of calcium carbonate and can become fossilised in limestone
How much limestone is all sedimentary rocks and how much carbon is locked up in. It?
10%
12%
What does the mAuna loa observatory do
Produces large amounts of data which can be used for analysis
What can autotrophs concert carbon dioxide into?
Carbohydrates another carbon compounds
