Carbon Cycle

Question 1

Carbon’s Importance

Answer 1

an essential element of life
- part of organic molecules of living organisms
– makes up 20% of total body weight
- basis of long chains of organic molecules that form membranes and walls of cells, constitute backbone of proteins, fats, carbohydrates & store energy for later use

Question 2

Carbon cycle

Answer 2

• movement of carbon from nonliving environment into living things & back (movement of carbon around the biosphere).

Question 3

Carbon Sinks (contain large quantities of matter)

Answer 3

atmosphere - carbon dioxide
ocean - carbonate & bicarbonate
rocks - coal & limestone
oil & natural gas
peat

Question 4

Flow Definition

Answer 4

• Processes that move matter between pools are known as flows.

Question 5

Fast components of the Carbon Cycle

Answer 5

• Involves processes that are associated with living organisms - biotic components

Question 6

Slow components of the Carbon Cycle

Answer 6

• involves carbon that is held in rocks, in soils, or as petroleum hydrocarbons (fossil fuels) – can be stored for millions of years - abiotic components

Question 7

Photosynthesis (by autotrophs)

Answer 7

Plants take in CO2 & incorporates carbon into their tissues
CO2 is converted into sugars
Producers convert CO2 in the atmosphere into carbohydrates during photosynthesis

Question 8

Respiration

Answer 8

• Returns CO2
• Sugars converted back into CO2
• Consumers obtain carbon from carbohydrates in the producers they eat
• During cellular respiration, some carbon is released back into the atmosphere as CO2 (fluxes)* this is measurable

Question 9

Respiration - Decomposition

Answer 9

• When organisms die, carbon that was part of the live biomass pool becomes part of the dead biomass pool
  decomposers break down dead matter which returns CO2 to water or air via respiration
• Carbon stored in bodies of organisms as fat, oils, or other molecules, may be released into soil or air when organisms dies

Question 10

Exchange

Answer 10

• CO2 in atmosphere & CO2 dissolved in water are constantly exchanged
• Basically an equal exchange of carbon

Question 11

Sedimentation

Answer 11

• Slow
  _ Calcium carbonate precipitates out of water as sediments, when dissolved, CO2 combines with calcium ions in water it becomes calcium carbonate
  largest carbon pool in slow part of carbon cycle
• Some carbon is stored in limestone, forming one of the largest “carbon sinks” on Earth.

Question 12

Burial or fossil fuel pools

Answer 12

Some carbon can be buried
Small fraction of organic carbon in dead biomass pool is buried & incorporated into ocean sediments before it can decompose into its constituent elements

Question 13

Extraction

Answer 13

• Human extraction of fossil fuels brings carbon to Earth’s surface, where it can be combusted
• These molecules may form deposits of coal, oil, or natural gas, which are known as fossil fuels
• Fossil fuels store carbon left over from bodies of organisms that died millions of years ago

Question 14

Combustion

Answer 14

• fossil fuels & plant matter are converted into CO2

by humans & natural combustion by fires or volcanoes - release carbon into atmosphere as CO2 or into soils as ash

Question 15

Human Effect - Combustion

Answer 15

• The best-known & most significant human alteration of the carbon cycle is the combustion of fossil fuels
• The excess CO2 in atmosphere acts to increase the retention of heat energy in the biosphere
  results in global warming - an increase in temperature of Earth

Question 16

Human Effect - deforestation

Answer 16

• Tree harvesting aka deforestation – trees store a lot of carbon in their wood both above & below ground – cutting & burning increases amount of CO2 in atmosphere
• To date, large areas of forests including tropical forests as well as North America & European temperate forests have been converted into pastures, grasslands, and croplands

Question 17

Ocean as Carbon Reservoir

Answer 17

The ocean is a huge sink for Carbon but turnover is high - dissolved Carbon → fast cycle
Ocean stores most of the carbon dioxide.

Question 18

Biggest Lithosphere reserve

Answer 18

Greatest lithospheric reserve: limestone - carbonate rock - sedimentary rock/sediments in the ocean = largest reservoir