Purpose of the carbon cycle?
Show how carbon moves from the atmosphere, through various animals and plants, then back into the atmosphere again.
The 6 processes in the carbon cycle
- Photosynthesis
- Respiration
- Feeding
- Decomposition
- Combustion
- Fossilisation
Explain the process of photosynthesis
- Captures energy from the sun
- Removes carbon dioxide from the atmosphere
- Incorporates CO2 into plant material in the form of glucose
What is glucose converted into
Glucose is converted into complex organic molecules such as:
- Carbohydrates
- Fats
- Proteins
Describe how does carbon circulate in through the food chain
- The carbon containing molecules are passed to consumers who feed on the plants
- This is done through food chains/ food webs
- It circulates the carbon to all living organisms
Describe the process of respiration in plants
- Glucose is broken down
- Energy released is used to form ATP ( molecule for storing and transferring energy in cells)
- The ATP is used to carry out diff. activities by the organism within the cell
- Thus, CO2 gas is the waste product and is given off into the atmosphere
What is the result of respiration?
The complex organic molecules containing carbon are broken down into small CO2 molecules, which is released into the atmosphere.
Simplified definition of decomposition
When organisms die, they begin to break down and decompose
Who carries out decomposition and give examples?
Microorganisms:
- Bacteria
- Fungi
Describe the process of decomposition
- The microorganisms break down the large complex biological molecules
- It then release smaller molecules into the surroundings
- Some molecules are used by the microorganisms as nutrients that are broken down during respiration
What is the result of decomposition
Carbon from the complex molecules that contain carbon would be released as CO2 back into the atmosphere
Equation for decomposition
A –> B + C + D […]
What is combustion?
When wood, fossil fuels such as coal/ oil and natural gas are burned
How are fossil fuels formed
- Formed from the remains of living organisms from millions of years ago
- Carbon in fossil fuels have been locked away, deep underground and was unavailable for release into the atmosphere.
Describe the process of combustion
- Ppl burn fossil fuels [coal/ oil in power plants, motorised vehicles such as cars/ planes/ trucks] or burn rubbish in incinerators
- Most of the carbon quickly enters the atmosphere as CO2 gas
The simplified definition of feeding
Moves carbon in the form of biological molecules along the food chain
Describe the process of fossilisation
- If condition are not favourable for the process of decomposition, dead organisms decay slowly/ not at all
- These organisms build up and, if compressed over millions of years, can form fossil fuels (coal, oil, natural gas)
Explain how a carbon atom in fossil fuel can end up in the cell of a plant.
a. Carbon in fossil fuel released as CO2 through combustion
b. When plant PHS, absorb the carbon
c. CO2 converted into glucose
