4.3 Flashcards
What happens to carbon in aquatic ecosystems
Carbon dioxide is soluble in water. It can combine with water to form carbonic acid. It can dissociate to form H+ & HCO3- ions which lowers the pH of water
How do autotrophs ensure that carbon dioxide always diffuses into their cells?
They continually using the CO2 in their cells in photosynthesis, maintaining the concentration gradient so that more CO2 diffuses in
How does carbon dioxide reach cells of terrestrial plants & aquatic plants?
Terrestrial plants: diffuses from air to stomata to air spaces in spongy mesophyll then dissolved in the water and then diffuses into cytoplasm
Aquatic plants: entire surface of leaves is permeable to CO2 so it diffuses directly from water into cells
How does peat form?
It forms when organic matter isn’t fully decomposed because of acidic/and or anaerobic conditions in waterlogged soils
Describe in stages how Coal is formed:
When vegetation died much of it didn’t decompose completely & formed peat
Over time it became buried & compressed to form lignite
Further compression & heat turned it into bitumous coal & anthracite
Describe in stages how oil & gas is formed:
Plankton in oceans sank to the seabed when they died
The layer of dead organic matter got covered with mud and only partially decomposed
This was compressed & heated forming natural gas & oil
Oil & gas are less dense than water so they moved up through porous rocks and formed reservoirs under impermeable rock
What happens to animals such as reef-building corals and molluscs?
Their soft body parts decompose quickly
In acid conditions the calcium carbonate dissolved away
In neutral or alkaline conditions calcium carbonate remains stable so it falls to the sea bed & over time becomes compressed into limestone
What is a carbon pool?
A reserve of an element
What is a carbon flux
the transfer of an element b/w pools
How is methane produced?
methanogenic archaeans in anaerobic environment
extraction of fossil fuels
melting of polar ice & perms frost
