Big Idea 18: Matter and Energy
Transformations
A. Living things all share basic needs for life.
B. Living organisms acquire the energy they need for life processes through
various metabolic pathways (photosynthesis and cellular respiration).
C. Matter and energy are recycled through cycles such as the carbon cycle.
Benchmark Number &
Descriptor
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SC.8.L.18.1
Describe and investigate the process of photosynthesis, such as the
roles of light, carbon dioxide, water and chlorophyll; production of food;
release of oxygen.
SC.8.L.18.2
Describe and investigate how cellular respiration breaks down food to
provide energy and releases carbon dioxide.
SC.8.L.18.3
Construct a scientific model of the carbon cycle to show how matter and
energy are continuously transferred within and between organisms and
their physical environment.
SC.8.L.18.4
Cite evidence that living systems follow the Laws of Conservation of
Mass and Energy.
Your Energy is My Energy
Cycling of Energy
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Energy enters the ecosystem from the sun and
exits after the organisms have taken as much as
they need.
Organisms release energy back into the biosphere
as heat.
This energy cycles round and round in order for the
Earth to survive!
The Carbon Cycle
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Carbon is the basis of life on Earth.
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99.9% of all organisms on the planet need carbon to survive.
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Carbon is continuously cycled and reused.
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Carbon can be found on Earth in the following locations:
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in living and dead organisms found in the biosphere
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carbon dioxide in the atmosphere
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organic matter in soils
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sedimentary rock deposits such as limestone, dolomite, and chalk in
the oceans as dissolved atmospheric carbon dioxide and as calcium
carbonate shells in marine organisms
The Carbon Cycle
Photosynthesis and respiration are the key processes in the carbon
cycle.
Carbon Cycle Breakdown
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Photosynthesis
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Process by which plants and other
autotrophs store the energy of sunlight
into sugars
Requires sunlight, water, and carbon
dioxide
Occurs in the leaves of plants in
organelles called chloroplasts.
The plant’s leaves use the light to make a
sugar called glucose.
Chemical formula
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6 CO2 + 6 H2O + E  C6H12O6 + 6 O2
Reactants = carbon dioxide, water, energy
(Sun)
Products = glucose (sugar), oxygen
During the process of photosynthesis,
oxygen is produced (We use this oxygen
to breathe).
Photosynthesis
A closer look
Carbon Cycle Breakdown
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Respiration
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Process by which organisms
utilize the products from the
process of photosynthesis
Requires glucose and oxygen
Occurs when consumers eat
producers to use the glucose for
energy and utilize the oxygen
Chemical formula
 C6H12O6 + 6O2 --> 6CO2 +
6H2O + energy
 Reactants = glucose, oxygen
 Products = carbon dioxide,
water, energy
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Respiration – A Closer Look
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Respiration is the process
by which the energy in the
bonds of nutrients are used
to synthesize ATP.
Respiration occurs
continuously in all cells of
all organisms.
Two main types
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Anaerobic – no oxygen
required
Aerobic – requiring
oxygen
Here food is broken down
completely into CO2.
Other Ways CO2 Enters the
Atmosphere
 Decomposers
are
also a key partner
in the carbon
cycle.
 Decomposers
break down
organic material
such as dead
animals or leaves.
CARBON
CYCLE
•A
closer look of how
Carbon is transported
through Earth’s
atmosphere.
•Carbon Cycle follows
Law of Conservation of
Mass/Energy
•There
is a set number
of Carbon (C) atoms in
Earth’s atmosphere.
•This element is
recycled through the
planet's resources.
Plants use Carbon Dioxide
and release Oxygen into the
atmosphere.
Animals eat plants, gain
energy (glucose), use oxygen,
and release Carbon dioxide.
Organisms die and
decompose, sending nutrients
to soil; plants grow from soil,
animals eat plants, etc.
Knowledge Check
What are some of the contributors to
atmospheric CO2?
 How is some of the CO2 removed from the
atmosphere?
 What is the relationship between producers
and consumers?
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Knowledge Check
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What are some of the contributors to atmospheric CO2?
 Animal respiration and factories
How is some of the CO2 removed from the atmosphere?
 Through the process of photosynthesis
What is the relationship between producers and
consumers?
 The products that producers create are used for the
survival of consumers, visa-versa.