4. Carbon Cycling

Question 1

What is the acronym for remembering the most important elements for life?

Answer 1

CHOP
Carbon, hydrogen, oxygen, phosphorous

Question 2

What does photosynthesis use and produce?

Answer 2

H2O and CO2 and produces glucose and oxygen

Question 3

What does respiration take and produce?

Answer 3

Takes glucose and oxygen and produces H2O and CO2

Question 4

Are organic carbons (glucose etc) reduced or oxidised?

Answer 4

Reduced, e.g. carbon dioxide to glucose by photosynthesis is reduction

Question 5

Are inorganic carbons (CO2, CO3, bicarbonate, carbonic acid etc) reduced or oxidised?

Answer 5

Oxidised, e.g. glucose to carbon dioxide by respiration is oxidation.

Question 6

What is oxidation?

Answer 6

Loss of electrons

Question 7

What is reduction?

Answer 7

Gain of electrons

Question 8

What is a redox reaction?

Answer 8

Swapping electrons

Question 9

What does large amounts of reduced sugars (organic carbons) imply about the environment they’re in?

Answer 9

Lots of oxygen somewhere else, since reduction processes such as photosynthesis produce oxygen as well as reduced carbons

Question 10

What reaction must happen alongside an oxidation reaction?

Answer 10

A reduction to balance out

Question 11

What is the meaning of the ‘oxidation state’ of an atom in a chemical compound?

Answer 11

Describes degree of oxidation, e.g. loss of electrons

Question 12

Is reduced (organic) carbon usually ‘hard or squishy’? What does this mean for their fossil potential?

Answer 12

Usually squishy, can enter fossil record or become coal (only plants)

Question 13

Is oxidised (inorganic) carbon usually ‘hard or squishy’?

Answer 13

hard

Question 14

Define decay.

Answer 14

The consumption of organic matter by fungi and microbes

Question 15

What process other than respiration balances out production of (reduced) organic carbon by photosynthesis?

Answer 15

Decay

Question 16

Describe the process of the carbon cycle within the oceans?

Answer 16

• Photosynthesis creates organic matter at the surface
• This sinks and decays back to CO2
• Eventually the carbon is recycled back to the surface

Question 17

What is the approximate duration of the ocean carbon cycle?

Answer 17

About 1000 years

Question 18

How are small amounts of carbon lost from the ocean carbon cycle?

Answer 18

Incorporated into ocean sediments and rock through the fossil record

Question 19

Briefly - what is the long term carbon cycle?

Answer 19

A process in which some reduced carbon does not decay and quickly return its carbon and oxygen to the atmosphere - instead it is stored long term

Question 20

What are some long term carbon sinks?

Answer 20

Organic C burial, silicate weathering, CaCO3 burial

Question 21

Why is removing carbon suggested to be the reason for current ‘ice age’? How?

Answer 21

Because there’s no evidence for increased volcanism on the long term scale to be adding more CO2.
Silicate weathering increase is suggested.

Question 22

What is the suggested reason that silicate weathering rates have increased

Answer 22

More exposed rock on the move (increased mountainous terrain at the moment)

Question 23

Why do flat rocks weather slower than mountainous terrain?

Answer 23

Weathered only by rain, angled rocks have runoff sediment, rockfall, frostcreep, and downslope movement

Question 24

What caused the Himalayan crunch?

Answer 24

India’s movement northward from Gondwana (relatively quickly)

Question 25

How do the Himalayan uplift rates of the last 5My compare to the 5My before?

Answer 25

At least twice as much, if not up to 5 times more.