Biology - Cycles within ecosystems ecology (4.10-11)

Processes of CO2 transferred into the atmosphere (4)

• Combustion

• Respiration of plants

• Respiration of animals

• Respiration of decomposers

Processes of CO2 removed from atmosphere

• Photosynthesis

Processes moving CO2 throughout the system (5)

• Feeding (plants to animals)

• Egestion/ excretion (animals to faeces)

• Death (animals to dead)

• Decomposition (dead organisms to decomposers)

• Fossilisation (dead organisms to fossil fuels)

Name the carbon stores (6)

• Plants

• Animals

• Faeces

• Dead organisms

• Decomposers

• Fossil fuels

Which biological molecules in organisms contain nitrogen?

• Proteins

• DNA

Why can’t plants access nitrogen directly from the air

• Very stable

• Triple covalent bond

Processes of removing nitrogen from the atmosphere (2)

• Nitrogen fixation (bacteria in root nodules of legumes) → NH3

• Nitrogen fixation (lightning or fertilisers) → NO3

Process of adding nitrogen to the atmosphere

• Dentrification (dentrifying bacteria in the soil)

What is nitrification

• Ammonia (NH3) → Nitrite (NO2) → Nitrate (NO3)

• Nitrifying bacteria in the soil

What are processes of moving nitrogen within the system (not atmosphere) (4)

• Feeding (plant protein → animal protein)

• Death (plant or animal protein to protein in dead organisms)

• Plants absorb nitrates (NO3 → plant protein)

• Nitrification (NH3 → NO2 → NO3)

what does protein in dead organisms become

Ammonia