Transcript Carbon Cycle - Alvinisd.net

Cycling of Matter
Carbon Cycle
Nitrogen Cycle
Ecosystems TEKS
• TEK 7.5 B – Demonstrate and explain the cycling of
matter within living systems such as in the decay of
biomass in a compost bin.
• Biomass is the material that makes up living organisms.
• Decomposition is when substances are broken down.
Decomposers are bacteria, fungi, earthworms, and
dung beetles.
• As material decomposes in a compost bin, heat, along
with other gases (CO2 & Nitrogen), are given off.
Composting provides natural and organic fertilizer
which is both healthy for the soil and environment. The
decaying process releases energy and recycles biomass.
• The Nitrogen, Carbon, and Water cycles demonstrate
and explain the cycling of matter within living systems.
Ecosystems TEKS
• TEK 7.6 A – Identify that organic compounds contain
carbon (C) and other elements such as hydrogen (H),
oxygen(O), nitrogen (N), phosphorus(P), and sulfur (S).
• Organic compounds are comprised of carbon and other
elements that are recycled due to chemical changes that
rearrange the elements for the particular needs of living
things.
• Inorganic compounds rarely contain the element carbon
and are from nonliving things.
Carbon Cycle
• Carbon is one of the most important elements on Earth.
• All living things have carbon in their cells. Organisms need
carbon to survive.
• However, Earth only has a certain amount of carbon.
Living things are constantly being born and growing, so
how do the increasing numbers of living things get the
carbon they need?
• Carbon (as well as other elements) moves between the
living and nonliving environment in cycles.
• The Carbon Cycle allows this to happen.
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Where does Carbon exist?
Atmosphere (air) as a gas called carbon dioxide.
Biosphere (the living environment) in the cells of organisms.
Geosphere (Earth’s crust) in the rocks.
Hydrosphere (liquid Earth) dissolved in water.
Atmosphere
• Oxygen (O2) makes up 20% of the atmosphere.
• When carbon is attached to two oxygen molecules, it
becomes carbon dioxide (CO2), which is toxic or
poisonous if animals or people breathe in too much of it.
• Plants remove CO2 from the air during photosynthesis.
Biosphere
• Carbon exists in the bodies of living things (plants, animals).
• Plants get the carbon they need because they create their own sugar
molecules (glucose) through photosynthesis.
• When animals eat plants, the animals get the carbon they need.
• Carbon becomes part of the cells of consumers through the food they
eat. When animals eat other animals who ate plants, the carbon is
passed along to them.
How does carbon get recycled into
the atmosphere?
3 ways
Respiration
(Animals Breathing)
• When plants perform photosynthesis, they release oxygen (O2)
into the air.
• Consumers breathe in and use this O2 as they break down the
sugars they eat. Animals then breathe out and give off CO2 into
the air so the plants can use it again.
• CO2 is returned to the atmosphere by respiration – when animals
breathe.
Decomposition (Decay)
• When an organism dies, the tissues, including carbon, are
broken down by decomposers, releasing CO2.
Combustion
(Burning)
• Burning wood or fossil fuels (oil, gas) releases large amounts
of CO2 into the atmosphere. Because they are made from
plants, they contain carbon, which is released as CO2. Cars
and factories contribute a lot.
• Combustion also happens in forest fires.
Carbon Cycle
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Combustion
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Cellular
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Decomposition
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Carbon Cycle Video
https://youtu.be/vrDekmRbBVk
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Nitrogen Cycle
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• Where does Nitrogen exist?
78%
• It is found in many places just like carbon,
and it gets recycled to be reused through the Nitrogen Cycle.
• Nitrogen is the main gas in the atmosphere, making up 78%.
• However, Nitrogen is in a form that plants or animals can’t
use. It must first be changed with the help of bacteria in the
soil and water into Nitrogen compounds that other living
things can use.
• Nitrogen fixation – the process that changes atmospheric
Nitrogen into Nitrogen compounds that are usable by living
things.
• 1. Lightning changes nitrogen gas in the atmosphere to
nitrogen compounds that fall to the ground when it rains.
• 2. Nitrogen-fixing bacteria in the soil converts it to usable
nitrogen compounds that plants can take in.
• 3. Animals eat the plants, getting the nitrogen compounds passed on
to them.
• 4. When an organism dies, decomposers break down the tissues. As
decomposition occurs, Nitrogen is given off as a gas and returned to
the atmosphere. It is also returned through animal waste as fertilizer
for new plants.
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