the carbon cycle

Question 1

what are the main reservoirs of the carbon cycle

Answer 1

1) the atmosphere- co2, methane, co
2) hydrosphere - hydrogen carbonate ions, dissolved co2
3) biosphere- carbohydrates, proteins, lipids
4) lithosphere- carbonaceous rocks, fossil fuels

Question 2

list the main processes of the carbon cycle

Answer 2

1) photosynthesis
2) respiration
3) food webs
4) fossilisation
5) combustion

Question 3

outline the process of photosynthesis

Answer 3

• captures light energy using pigments such as chlorophyll
• converts low energy substances such as co2 and water into high energy carbohydrates which can be converted into other substances such as proteins and lipids

Question 4

outline the process of respiration

Answer 4

• releases energy that was captured in photosynthesis which is used to drive metabolic processes
• aerobic respiration returns carbon back into the atmosphere as co2

Question 5

outline the process of food webs

Answer 5

some of the carbohydrates, proteins and lipids produced by plants are eaten by herbivores which may then be eaten by carnivores- the feeding relationships transfer the carbon through the food webs

Question 6

outline the process of fossilisation

Answer 6

• the incomplete combustion of dead organic matter often under anaerobic conditions can produce substances that form long term carbon stores such as fossil fuels

Question 7

outline the process of combustion

Answer 7

• the burning of organic materials releases carbon dioxide

- natural fires in forests and grasslands may be started by lightening

Question 8

list the ways that humans affect the carbon cycle

Answer 8

1) changes in photosynthesis
2) changes in aerobic respiration
3) changes in anaerobic respiration
4) carbonic acid conc in the sea
5) methane release from fossil fuels
6) combustion
7) biomass movements

Question 9

outline how human activity affects photosynthesis

Answer 9

• deforestation removes uptake of co2 from the atmosphere into biomass
• afforestation increases uptake of co2 from the atmosphere into biomass
• algae living on the underside of sea ice absorb light energy GCC reduces ice reducing algae increasing co2 in atmosphere

Question 10

outline how human activity affects aerobic and anaerobic respiration

Answer 10

1) plowing increases oxygen supply to decomposers in the soil so decomposition occurs more rapidly

2)

• absence of oxygen the respiration of anaerobic soil organisms releases methane gas which gradually oxidizes to co2
• rice paddy fields
• land fill sites
• waterlogged fields

Question 11

outline how human activities affect carbonic acid conc in the sea

Answer 11

• human activities affect the concentration of co2 in the atmosphere which alters the processes to create a new dynamic equilibrium
• dissolved co2 is in equilibrium with carbonic acid
• as atmospheric co2 increases dissolved co2 increases which increases hydrogen ions in the sea

Question 12

outline how human activities affect methane release from fossil fuels

Answer 12

released during fossil fuel extraction

Question 13

what are some management techniques of the carbon cycle

Answer 13

1) conservation of biomass carbon stores
2) use of alternative fossil fuels
3) carbon sequestration

Question 14

give some examples of biomass carbon stores which need to be conserved to help manage the carbon cycle

Answer 14

1) peat bogs

2) forests

Question 15

give some examples of carbon sequestration methods

Answer 15

1) large scale afforestation

2) carbon capture and storage

Question 16

outline carbon capture and storage

Answer 16

the capturing of co2 so that it is not released into the atmosphere for example post combustion eg dissolving co2 into a solvent, high-pressure membrane filtration or adsorption processes