7. Ecology: Systems of Organisms
7.5. The Carbon Cycle
The carbon dioxide content in the atmosphere is slightly more than 0,04 %
Plants, algae and som bacteria "harvest" sunlight. Carbon is assimiliated in glucose.
- Carbon dioxide + water + light → glucose + oxygen
- 6CO2 + 6H2O + hν → C6H12O6 + 6O2
Animals eat plants.
Glucose is used (in animals as well as plants):
- As building material in the cell.
- As energy reserve: It is oxidized (combusted), and energy is released. The animal "harvests" the energy released.
- Glucose + oxygen → carbon dioxide + water + energy
- C6H12O6 + 6O2 → 6CO2 + 6H2O + energy
The carbon dioxide is exhaled, returned to the atmosphere.
Animals, plants die.
- Decomposers break down dead organisms.
- Carbon dioxide is returned to the atmosphere through cellular respiration.
Dead organisms may be packed under high pressure under millions of years.
- Oil, coal, natural gas is formed (fossil fuels)
When combusted, for example in combustion engines, carbon dioxide forms again, and is returned to the atmosphere.
Carbon dioxide may be dissolved in water. Carbonic acid, H2CO3, is formed:
- CO2 + H2O → H2CO3
Carbonic acid gives rise to carbonates:
- Hydrogen carbonate, HCO3–
- Carbonate, CO32–
Carbonates, spec. calcium carbonate (CaCO3) is used in animals' shells and corals.
- Shells & corals may pack under high pressure and long time ⇒ Limestone
- Carbonates are re-formed.
- Carbon dioxide may be returned to the atmosphere.
Limestone is important for the ecology on land!
- 1. The Fundamentals of Life
- 2. Cellular Structure and Function
- 3. Cellular Genetics
- 4. Mendelian Genetics
- 5. Evolution and Systematics
- 5.1. Roadmap to a Theory of Evolution
- 5.2. The Pillars of Evolution
- 5.3. Evidence for Evolution
- 5.4. Convergent and Divergent Evolution
- 5.5. Coevolution
- 5.6. Stabilizing and Disruptive Selection
- 5.7. Speciation
- 5.8. How to Build a Family Tree
- 5.9. The History of Life
- 5.10. The Formation of Life
- 5.11. The Divisions of Life
- 5.12. Plant Systematics
- 5.13. Animal Systematics
- 5.14. Chordate Systematics
- 5.15. Human Evolution
- 6. Ethology and Behavioural Ecology
- 7. Ecology: Systems of Organisms
- 7.1. Ecosystems
- 7.2. Nutritional Chains and Food Webs
- 7.3. Flow of Energy in an Ecosystem
- 7.4. The Water Cycle
- 7.5. The Carbon Cycle
- 7.6. The Nitrogen Cycle
- 7.7. The Phosphorous Cycle
- 7.8. Populations: Size and Growth
- 7.9. Communities. Living Together
- 7.10. Ecological Succession
- 7.11. From Bedrock to Litter
- 7.12. The Lakes
- 7.13. The Oceans and Seas
- 7.14. Climate and Biomes
- 8. Environmental Science
- 9. Viruses and Biotechnology
- 10. Plant & Fungal Physiology
- 10.1. The Organs of the Plants
- 10.2. Plants With and Without Seeds
- 10.3. The Root. How the Plant Absorbs Water and Nutrients
- 10.4. The Trunk and Water Transport
- 10.5. Structure and Function of the Leaf
- 10.6. Photosynthesis
- 10.7. How Plants Grow
- 10.8. How Plants Reproduce
- 10.9. Classification of the Fungi
- 10.10. How Fungi Reproduce
- 10.11. Fungal Parasites and Pathogens
- 11. Human Physiology
- 11.1. Physiology Basics
- 11.2. The Nervous System
- 11.3. The Senses
- 11.4. The Endocrine System
- 11.5. Food and Digestion
- 11.6. The Locomotor System
- 11.7. Gas Exchange and Circulation
- 11.7.1. Respirational Systems
- 11.7.2. Human Respiration
- 11.7.3. Circulation in Different Animals
- 11.7.4. The Human Circulatory System. Heart, Blood Vessels and Blood Pressure
- 11.7.5. Activity in the Capillaries
- 11.7.6. Blood Constituents
- 11.7.7. Blood Groups
- 11.7.8. Coagulation
- 11.7.9. Some Blood Diseases
- 11.7.10. Water Balance. Kidneys
- 11.8. The Immune System
- 11.9. Sex, Love, and STDs