Matter Cyclesmatter

Matter Cycles

• The Law of Conservation of Matter states that matter is neither created or destroyed

• In biological systems, this also holds true• We will be focusing on four matter cycles, also

called nutrient or biogeochemical cycles• These are the Carbon, Water (hydrological),

Nitrogen and Phosphorus cycles

The Carbon Cycle

The Carbon (C) Cycle

• Even though it cycles we are going to start in the atmosphere

• CO2 (carbon dioxide) in the atmosphere is picked up by photoautotrophs and turned into sugars

• These sugars support the building of C containing molecules that make up living organisms

• Another organism eats the plants, transferring the C to the next organism

The Carbon (C) Cycle• This C may be passed on to another organism if it

gets eaten• CO2 is reenters the atmosphere by cellular

respiration from most organisms• Dead organisms and waste decomposes and

more CO2 is reenters the atmosphere

• Fossil fuels are underground stores of C, when dug up are burned (combustion) as petroleum, natural gas or coal; they add additional C as to our environment as CO2

• Excess CO2 is absorbed in bodies of water

The Carbon (C) Cycle

• CO2 is an important Greenhouse gas helping keep the planet at a relatively stable temperature

• Excess burning of fossil fuels by industry and transportation has increased the amount of ground level and atmospheric C on our planet and may be accelerating climate change.

The Water Cycle (hydrological)

The Water Cycle (hydrological)

• Evaporation-water enters the atmosphere• Precipitation-water condenses and leaves the

atmosphere as rain, sleet or snow and ends up on land and can –– Runoff into surface water or– Infiltrate (or percolate) into land as groundwater or– Freeze and accumulate as ice

• Or ends up in the ocean or other surface water• Transpiration –water leaves plants and enters

the atmosphere

The Water Cycle (hydrological)

• Humans interrupt the water cycle by • Over pumping ground water• Creating many impervious surfaces (buildings,

concrete and asphalt) so that water cannot reenter the ground and refill ground water

• Polluting available surface and ground water• Building dams• Growing thirsty plants where they are not

adapted to grow

The Water Cycle (hydrological)

The Nitrogen Cycle

The Nitrogen Cycle• 78% of the atmosphere is Nitrogen, N2, is the

major source of this vital element which is essential to make proteins in all living organisms

• There is ONLY one kind of organism that can take N2 from the atmosphere and they are called N fixing bacteria

• These soil dwelling N fixing bacteria then make N available to plants

The Nitrogen Cycle• Plants use the N, now as nitrate or ammonium

and make proteins• These plants are eaten and the N as protein is

passed on to the consumer• Lightning strikes can also fix atmospheric N2 in

the soil• N2 can return to the atmosphere by denitrifying

bacteria in wet soil• N can also returned to the soil by

decomposition of waste or dead organisms

The Nitrogen Cycle• Humans impact the N cycle by• Manmade fertilizer high in N• Burning of petroleum by internal combustion

engines (cars) produces large amounts of N compounds that cause acid rain by forming nitric acid when mixing with water in the atmosphere

The Phosphorus Cycle

The Phosphorus Cycle

• Unlike all the other matter cycles, Phosphorus, P, NEVER cycles through the atmosphere

• P is important both as part of DNA and cell membranes

• P is MOSTLY found in rock• P is an important limiting factor in plant

growth

The Phosphorus Cycle

• P is picked up by plants from the soil• The plants are eaten and P is obtained by the

consumers from eating the plants• Then the P goes to the next consumer • P renters the ground by waste or

decomposition• Weathering of rock is vital for the P cycle as is

the water cycle for the movement of P

The Phosphorus Cycle

• Humans impact the P cycle by adding large amounts of inorganic fertilizer high in phosphorus which enters surface and ground water

• Farm animal waste from large farms is high in P and can also enter the water cycle

• These large amounts of P can cause eutrophication, rapid and large growth plants and algae, of bodies of water which chokes out other aquatic life forms

Cycles Wrap-up• biogeochemicals cycles video