CIE iGCSE Co-ordinated Sciences-B18.3 Carbon cycle- Study Notes- New Syllabus
CIE iGCSE Co-ordinated Sciences-B18.3 Carbon cycle – Study Notes
CIE iGCSE Co-ordinated Sciences-B18.3 Carbon cycle – Study Notes -CIE iGCSE Co-ordinated Sciences – per latest Syllabus.
Key Concepts:
Core
- Describe the carbon cycle, limited to: photosynthesis, respiration, feeding, decomposition, formation of fossil fuels and combustion
CIE iGCSE Co-Ordinated Sciences-Concise Summary Notes- All Topics
The Carbon Cycle
📌 Introduction
The carbon cycle shows how carbon moves through living organisms, the atmosphere, and the Earth.
Key processes include photosynthesis, respiration, feeding, decomposition, fossil fuel formation, and combustion.
🔄 Key Processes
- Photosynthesis 🌱
Plants (producers) remove CO₂ from the atmosphere.
Carbon is used to make glucose.
Equation: CO₂ + H₂O → C₆H₁₂O₆ + O₂ - Respiration 🐾
All living organisms release CO₂ back into the atmosphere when they break down glucose for energy. - Feeding 🍴
Carbon moves along food chains as animals eat plants and other animals. - Decomposition 🍄
Dead plants and animals are broken down by decomposers.
Carbon is returned to soil or released as CO₂. - Formation of Fossil Fuels ⛏️
Over millions of years, dead plant and animal material is converted into coal, oil, and gas.
Stores carbon underground. - Combustion 🔥
Burning fossil fuels releases CO₂ back into the atmosphere, contributing to greenhouse gases.
📊 Summary Table
| Process | Carbon Movement |
|---|---|
| Photosynthesis | CO₂ → Glucose (plants) |
| Respiration | Glucose → CO₂ (all organisms) |
| Feeding | Carbon moves along food chain |
| Decomposition | Dead matter → CO₂/soil |
| Fossil fuel formation | Dead matter → coal, oil, gas |
| Combustion | Fossil fuels → CO₂ (atmosphere) |
⚡ Quick Recap
Sun + CO₂ → plants → animals → decomposers → fossil fuels → combustion → CO₂
Carbon cycles between living things, soil, and atmosphere.
Memory tip: “Photosynthesis pulls CO₂ in, respiration and combustion put it out.”