13.5 Cycling of Matter
Atmospheric Gases
13.5 Cycling of Matter
Atmospheric Gases
• Nitrogen- promotes plant growth and is an important
ingredient in the chemicals that make up living
things.
• Oxygen- is necessary for animals and plants to
perform life processes.
• Other- includes carbon dioxide, argon, water vapor
and other trace gasses. Plants use carbon dioxide
and water to make food.
13.5 Cycling of Matter
III. Carbon Cycle
1. Carbon is the building block of
life.
a. The carbon cycle moves carbon
from the atmosphere, through the
food web, and returns to the
atmosphere.
b. Carbon is emitted by the burning
of fossil fuels (like oil, gasoline,
and coal)
13.5 Cycling of Matter
Carbon Cycle: notice photosynthesis and
respiration are back … they both involve CO2
(now we’re looking at the C for carbon)
carbon
dioxide
in air combustion
respiration
photosynthesis
respiration
decomposition
of organisms
fossil fuels
photosynthesis
carbon dioxide
dissolved in water
13.5 Cycling of Matter
IV. The Nitrogen Cycle
1. The nitrogen cycle mostly takes place underground.
2. In the atmosphere when lightning strikes it exites the
Nitrogen molecules and brings them down to the ground.
3. Some bacteria convert gaseous nitrogen into ammonia
in
through a process called nitrogen
nitrogen
fixation.
atmosphere
animals
– Some nitrogenfixing bacteria
live in
nodules on the
roots of plants;
others live
freely in
the soil.
plant
nitrates
nitrogen-fixing
bacteria in
decomposers
nitrifying
roots
bacteria
ammonification
nitrites
nitrogen-fixing
ammonium
bacteria in soil
nitrifying
denitrifying
bacteria
bacteria
13.5 Cycling of Matter
3. Ammonia released into the soil is transformed
into ammonium.
4. Nitrifying bacteria change the ammonium
into nitrate.
– Nitrogen moves
through the
food
web and
returns
to the soil
during
decomposition.
nitrogen in
atmosphere
animals
plant
nitrogen-fixing
bacteria in
decomposers
roots
ammonification
nitrogen-fixing
ammonium
bacteria in soil
nitrifying
bacteria
nitrates
nitrifying
bacteria
nitrites
denitrifying
bacteria
13.5 Cycling of Matter
If Needed
• http://www.youtube.com/watch?v=1YAOT92wuD8
• http://www.youtube.com/watch?v=fyfN9t_E0w8