The Carbon Cycle | A2 Biology Revision

• Energy enters an ecosystem via the Sun
• Energy lost as heat - one directional flow
• There's only a certain quantity of Nutrients - so carbon and nitrogen need to be recycled
• Nutrient is taken up by the producer
• Producer incorporates it into simple inorganic molecules then into complex organic 
• Producer eaten
• Nutrient passes to the consumer

SAPROBIOTIC microorganisms - decomposers

(death)

• decomposers release the nutrient in original simple form

CYCLE BEGINS AGAIN

0.04% Carbon Dioxide in the atmosphere - greenhouse gas, contributes to global warming

Plants remove Carbon Dioxide from the atmosphere to build macromolecules

Macromolecules: Fats, Proteins, Carbohydrates

CO2 returned to the air through respiration

Short term fluctuations

Carbon dioxide levels globally vary because:

• Combustion of fossil fuels
• Deforestation

Aimed specifically at AQA A Level Biology