Biogeochemical Cycles

Biogeochemical Cycles

Water Cycle

Carbon Cycle

Nitrogen Cycle

Matter Recycling

An ecosystem survives by a combination of energy flow and matter recycling

Biogeochemical cycles move all nutrients through air, water, soil, rock and living organisms

Water Cycle Terminology

• Evaporation - water heating up and turning to gas

• Transpiration - water evaporation from the leaves of plants

• Condensation - water vapor cooling to form a cloud

• Precipitation - any moisture falling to Earth

Water Cycle

• Driving force is the sun

• Water is the most important abiotic component of an ecosystem

• Water cycle is critical to other cycles

• Water is critical for photosynthesis

• Human cells are made of water

• Amount of water on earth is constant

Effects of Human Activities on the Water Cycle

• Using too much freshwater/groundwater reserves

• polluting water

• contributing to climate change

Multiple Select

What two ways is water put into the atmosphere? (check both)

• evaporation

• condensation

• precipitation

• transpiration

Multiple Choice

Where does the energy to drive the water cycle come from?

• Earth's interior

• The sun

• Plate tectonics

• Photosynthesis

Multiple Choice

The amount of water on Earth is

• Always the same

• Constantly changing

• Steadily increasing

• Steadily decreasing

Carbon Cycle

The circulation of carbon between the living organisms and the non-living components of ecosystems.

Carbon Cycle

• Cellular Respiration - a process that makes energy (ATP) & involves a gas exchange

• Photosynthesis - the process of using sunlight to make glucose from CO₂ and water

• Combustion - process of burning fossil fuels (releases CO₂ & contributes to climate change)

Why is the Carbon Cycle Important?

The Primary function: to maintain a balance of carbon in nature

Carbon is an important component of proteins, lipids, DNA, and carbohydrates - the energy for living things!

Carbon dioxide helps to create a beneficial "greenhouse effect" to maintain Earth's temperature

Human Impact on the Carbon Cycle

• Humans alter the carbon cycle by adding excess CO₂ to the atmosphere by burning fossil fuels

• Clearing vegetation faster than it is replaced (less photosynthesis = more CO₂)

Multiple Select

What are two ways that CO₂ is put into the atmosphere? (check both)

• Cellular Respiration

• Photosynthesis

• Combustion

• Transpiration

Multiple Choice

Which of these processes removes CO₂ from the atmosphere?

• Cellular Respiration

• Evaporation

• Combustion

• Photosynthesis

Multiple Choice

In which process is Carbon transformed into chemical energy?

• Respiration

• Photosynthesis

• Primary Production

• Secondary Production

The Nitrogen Cycle

The nitrogen cycle is a proces through which nitrogen is converted to many forms, passing from the atmosphere to the soil to organisms and back to the atmosphere

Nitrogen Cycle

• ~ 76% of the atmosphere is nitrogen gas, but it is not in a usable form

• Bacteria are the only organisms that can use nitrogen directly from the environment

• Some plants have a symbiotic relationship with bacteria that can help fix nitrogen for them & the plant provides carbohydrates for the bacteria

Nitrogen Cycle Terminology

Nitrogen fixation - nitrogen gas in atmosphere to ammonia (bacteria in soil, lightning)

Nitrification - ammonia to nitrate (bacteria in soil)

Assimilation - absorption of ammonia and nitrate by plants

Ammonification - breakdown of dead organisms returns nitrogen to soil (bacteria and fungi) as ammonia

Denitrification - conversion of ammonia back to nitrogen gas (decomposers)

Importance of the Nitrogen Cycle

• Nitrogen is an essential component of amino acids and DNA

• Chlorophyll molecules - essential for photosynthesis - contain nitrogen

Human Impact on the Nitrogen Cycle

• Humans add nitrous oxide to the atmosphere from vehicles and factories which contributes to acid rain

• Excess addition of nitrogen through the use of fertilizers have negative impacts in ecosystems

Eutrophication

Too much nitrogen in water causes algae blooms, which block sun in aquatic ecosystems, causing plants and animals to die

Multiple Choice

Which type of organism is essential to fixing nitrogen to a usable for for other organisms?

• trees

• fungus

• algae

• bacteria

Multiple Choice

What is the process of combining nitrogen gas with other elements to make nitrogen into usable compounds?

• nitrogen composition

• nitrogen fixation

• ammonia

• denitrification

Multiple Choice

What process returns nitrogen from plants and animals to the soil and the atmosphere?

• decomposition

• precipitation

• condensation

• bacteria

Multiple Select

Nitrogen is used to produce which biomolecules? (check all that apply)

• carbohydrates

• lipids

• proteins

• nucleic acids