Biogeochemical cycle notes

Symbiosis Warm-up

  • Review of symbiosis, focusing on different types of symbiotic relationships.

  • Examples include: Oxpeckers and zebras, tapeworms and animals, spider crabs and algae, remora and sharks, bees and flowers.

Oxpecker and Zebras

  • Oxpeckers eat ticks and parasites on zebras.

  • Oxpeckers benefit by getting food; zebras benefit from pest control.

  • Type of symbiotic relationship: Mutualism.

Tapeworm and Animals

  • Tapeworms live inside the intestines of animals (cows, pigs, humans).

  • Tapeworms eat the host's digested food, depriving the host of nutrients.

  • Type of symbiotic relationship: Parasitism.

Spider Crab and Algae

  • Algae live on spider crabs' backs, camouflaging them.

  • Algae benefit by having a place to live; crabs benefit from camouflage.

  • Type of symbiotic relationship: Mutualism.

Remora and Shark

  • Remora fish eat scraps left by sharks.

  • Sharks are not harmed or helped by remoras.

  • Type of symbiotic relationship: Commensalism.

Bee and Flower

  • Bees gather nectar from flowers for food and collect pollen on their bodies, pollinating other plants.

  • Bees and flowers both benefit.

  • Type of symbiotic relationship: Mutualism.

Biogeochemical Cycles

  • How nutrients cycle through the environment.

  • Key components: Sunlight, photosynthesis, decay, animal respiration, organic carbon.

Honors Biology - Matter Recycling in Ecosystems

  • Recognizing the flow of matter and how it is recycled through the ecosystem, including the carbon cycle and nitrogen cycle.

  • Carbon cycle components: combustion, erosion, decomposition, respiration, photosynthesis.

  • Nitrogen cycle components: nitrogen fixation, denitrification.

Carbon Cycle Notes

  • The cycling of carbon through an ecosystem.

  • Key components: Carbon dioxide (CO2) in the atmosphere, marine plankton remains, photosynthesis, cellular respiration, combustion, dissolved CO2 in water, limestone, fossil fuels.

Key Terms

  • CO2: Carbon Dioxide.

  • Photosynthesis: Process by which light energy is converted to chemical energy, producing sugar and oxygen from carbon dioxide and water.

  • Formula: 6CO2 + 6H2O + Energy \rightarrow C6H{12}O6 + 6O2

  • Cellular respiration: Using oxygen to break down food.

  • Combustion: Burning fossil fuels (coal, oil, natural gas).

  • Erosion: Limestone erodes, releasing carbon.

The Carbon Cycle

  • CO2 is used during photosynthesis by plants, algae, and bacteria.

  • CO2 returns to the air and water through:

    • Cellular respiration

    • Combustion

    • Erosion

Carbon Cycle Scenario 1

  • Cutting down a forest to build a hotel would affect the carbon cycle.

Carbon Cycle Scenario 2

  • Taking the train to work instead of driving a car would affect the carbon cycle.

What's the Deal with Carbon?

  • Video (3:03) about carbon.

The Nitrogen Cycle

  • Key components include atmospheric nitrogen (N2), plants, denitrification, denitrifying bacteria, nitrates (NO3), animals, death, waste (urine and feces), decomposition, nitrogen fixation, decomposers, ammonification, nitrogen-fixing bacteria in plant roots, nitrifying bacteria, nitrification, ammonia (NH3).

Background Information

  • Nitrogen gas (N2) makes up 78% of Earth’s atmosphere.

  • Most organisms cannot use N2 in this form, thus rely on bacteria for nitrogen fixation, which binds nitrogen to hydrogen to form ammonia (NH3).

  • Nitrogen-fixing bacteria are found in the nodules on the roots of beans, birch and alder trees and some other plants.

Nitrogen Cycle Processes

  • Ammonification

  • Nitrogen Fixation

  • Nitrification

  • Assimilation

  • Denitrification

How the Nitrogen Cycle works

  • Nitrogen Fixation: Bacteria converts nitrogen to ammonia.

  • Nitrification: Bacteria converts ammonia to nitrate.

  • Assimilation: Nitrate is taken up by the plant’s roots.

  • Denitrification: Bacteria convert nitrate to nitrogen gas that goes back into the atmosphere.

  • Ammonification: Bacteria produces ammonia during the decay of urine.

Nitrogen Cycle Scenario 1

  • Livestock farming creates a large amount of animal waste which affects the nitrogen cycle.

Nitrogen Cycle Scenario 2

  • A farmer over-fertilizes his crop and leaves excess nitrates in the soil, which impacts the nitrogen cycle.