4.3 Carbon Cycling

List some features of Carbon in relation to carbon cycling

* is the backbone or all organic biomacromolecules
* 2nd most abundant molecule (aside oxygen)
* forms the chemical basis of all things
* is in many abiotic and biotic parts of an ecosystem

Reservoir / sink

a place where a certain element has pooled / accumulated e.g carbon sink

What is Carbon fixation

the process where photosynthesis has the effect of reducing atmospheric CO2

* autotrophs absorb CO2 via phot and release C molecules for consumers to consume

How does the absorption of CO2 work

* phot reduces the amount of CO2 inside the autoroph therefore the concentration of CO2 is higher in the external environemnt
* since CO2 automatically diffuses from high to low conc, it will flow into the plant
* the cycle continues

Peat

partially decomposed plant material which can be used as fossil fuel

How is peat formed

when organic matter is not fully decomposed: bc of anaerobic conditions in waterlogged soil - there is no oxygen therefore anaerobic

What are some uses of Peat

* can be cut out of the ground, dried and turned into fuel
* is usually rich molecules that should have been decomposed but weren’t and left behind → peat
* is considered a non renewable energy bc it take thousands of years to form

What happens when CO2 is soluble in H2O

* can remain gas or cobines to form H2CO3} H+ HCO -
* HCO - and CO2 are absorbed by aquatic plants and used in phot to create carbs and cc

Lithification

transformation of sediments into rock

Outline the process of lithification

* heat and pressure cause chemical transformations
* molecules are compacted and rearranged into hydrocarbonds so they can form long chain
* (C-H bonds = strong therefore can release more energy when burning
* e.g coal is dead plants under h/p of rocks / dirt

Anoxic

a condition where aquatic environments do not contain dissolved oxygen e.g petrol

Limestone

* when animals that contain CaCO3 die their soft bodies decompose and dissolve to be deposited and limestone can form on the sea bed
* is a major ingredient in cement

Flux

a process that moves an element from a reservoir/sink to another e.g carbon flux

Features of CO2

* is released in cellular resp
* diffuses out of cells into the water / atmosphere

Features of CH4 Methane

* produced in anaerobic conditions by methanogenic bacteria
* can either accumulate underground or diffuse into atmosphere

Why is the concentration of methane low in the atompshere?

because the molecules of methane persist for around 12 years