The carbon cycle
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Explainer Video
Summary
The carbon cycle
In a nutshell
The carbon cycle is the process in which carbon is recycled on Earth. There are a variety of processes, which release or take in carbon from the environment. Naturally-occurring biological processes and human activity contribute to the carbon cycle.
Release of carbon into the atmosphere
The compound carbon dioxide () contains carbon and is the main component of the carbon cycle. Carbon, in the form of , is released into the atmosphere when:
- Organisms respire
- Dead matter or waste is decomposed by respiring microorganisms
- Fossil fuels are burned (human activity)
Tip: all organisms respire to release energy; the word equation for aerobic (with oxygen) respiration is:
Role of photosynthesis in the carbon cycle
Photosynthesis is a process in which plants convert light energy from the sun into chemical energy in the form of sugars. Photosynthesis occurs in the chloroplasts of plant cells. Light energy from the sun is used to convert carbon dioxide from the atmosphere into oxygen and glucose.
The equation for photosynthesis is:
The carbon cycle
The process by which carbon on Earth is recycled is described below.
| 1. | Carbon dioxide in the atmosphere |
| 2. | Photosynthesis occurs in plants which takes in carbon dioxide from the atmosphere |
| 3. | Fossilisation of dead matter |
| 4. | Carbon dioxide is stored within fossil fuels |
| 5. | Decay of dead matter and waste |
| 6. | Decay of dead matter and waste releases carbon dioxide into the atmosphere |
| 7. | Vegetation is eaten by animals |
| 8. | Carbon dioxide is released into the atmosphere via respiration |
| 9. | Burning of fossil fuels releases carbon dioxide into the atmosphere |
FAQs - Frequently Asked Questions
Where does photosynthesis occur in a plant?
Photosynthesis occurs in the chloroplasts of plant cells.
What is the role of photosynthesis in the carbon cycle?
Plants use up carbon dioxide (with water) during photosynthesis to make glucose and oxygen.
What is the carbon cycle?
The carbon cycle is the process in which carbon is recycled in the atmosphere.