Lec 9 and 10: The Carbon cycle

Question 1

What natural linkage in the organic carbon cycle takes place in the long geological term?

Answer 1

Contrary to the rest of the natural linkages in the organic cycle, the fossil fuels act on a long term basis.

Question 2

What is the founding aspect of organic molecules and all living organisms?

Answer 2

They all contain carbon, it is the backbone of organic life

Question 3

How does Carbon make its way from the inorganic reservoirs to the organic sources

Answer 3

Photosynthesis

Question 4

what is the product of cellular respiration?

Answer 4

carbon dioxyde, water and ATP

Question 5

what is humus?

Answer 5

• organic component of soil
• composed of partially decomposed organic molecules
  
  • carbon-based molecules and other elements

Question 6

what does decomposition entail?

Answer 6

• Complex organic molecules broken down into simpler compounds:
  
  • releases atmospheric CO2 through cellular respiration
  • some carbon deposited in the soils as humus

Question 7

explain how fossil fuel forms

Answer 7

It forms in 4 steps:
1. dead organic matter buried by sedimentation before it can be fully decomposed

2. increasing build-up of sediments → increasing weight compressing organic matter, moves organic matter deeper within the crust (increasing heat exposure)
3. increased compression and heat →removes trapped water and gases, transforms larger carbon molecules to smaller ones
4. what remains is concentrated carbon with a minority of other elements
   1. coal : 60-80% carbon
   2. Oil: 80-85% carbon

Question 8

Why does combustion contribute to global warming

Answer 8

Because its end product is a greenhouse gas : CO2

Question 9

Why are fossil fuels so energy dense and so great for combustion

Answer 9

Because they have a high carbon concentration

Question 10

Give an example of natural combustion that has always been present, in balance with the inorganic cycle

Answer 10

• natural combustion of fossil fuels like a coal seam fire
• burning of vegetation

Question 11

what does an old growth forest look like?

Answer 11

• Huge trees with thick bark
• Distance between trees
• ferns (very wet)

Question 12

Why does an old forest resist better to wild fires?

Answer 12

1. because their bark is so thick
2. because of the distance, the fire is not fed enough to keep on growing
3. the root system of the trees is much bigger and deeper so it is easier to recover afterwards because it can still feed the plants

Question 13

What is a clear example showing this natural relation between fires and forests

Answer 13

Some species have evolved so that their cones only open up when a certain heat level is reached, it opens up and releases the seeds therefore planting a new generation for the forest to recuperate after the fire

Question 14

What is the biological pump?

Answer 14

it is the cycle of photosynthesis, cellular respiration and decomposition and the formation of fossil fuels but in a marine ecosystem

Question 15

what is the name of the photosynthetical organisms in water?

Answer 15

Phytoplankton

Question 16

what is unique to the marine ecosystems?

Answer 16

The formation of calcium carbonate! just like in the inorganic carbon cycle !

Question 17

What happens at night (and day but in the opposite) t in oceans that contributes to the carbon movement

Answer 17

• movement of living organisms between the surface and deeper waters

Question 18

why are seasonal changes greater in the northern hemisphere?

Answer 18

because there are more continents, more plants and therefore more differences

Question 19

what is ocean acidification?

Answer 19

It is the increase in H+ ions in the ocean resulting from the augmentation of co2 in the atmosphere (that then dissolves in the ocean)

Question 20

what is the greening hypothesis?

Answer 20

the hypothesis that CO2 can fertilize plants and enhance plant growth,
In the lab, it worked! but in reality it doesn’t reflect the same
FACE systems

Question 21

Why is ocean acidification a problem?

Answer 21

Impact on Marine Life: Increased acidity affects the ability of marine organisms, such as corals, mollusks, and some plankton species, to build and maintain their calcium carbonate structures (like shells and skeletons). This can lead to weaker shells and increased mortality rates

at a low enough pH, the shells can start to dissolve, these shells are crucial for the first layer of the “marine food chain”, a change at that level can disrupt the entire ecosystem

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