Cycling of Matter Resources
Teaching Targets
 TSW understand that matter continually cycles though the ecosystem, moving through
its abiotic and biotic parts. Within a natural or designed system, the transfer of energy
drives the motion and/or cycling of matter.
 TSW recognize that decomposers obtain energy from the breakdown of carboncontaining detritus, such as fallen leaves, feces, urine, or dead organisms. Thus,
decomposers recycle nutrients from dead plant or animal matter back to the soil in
terrestrial environments or the water in aquatic environments.
 TSW demonstrate the cycling of matter within living systems such as in the decay of
biomass in a compost bin.
 TSW explain the cycling of matter within living systems such as in the decay of
biomass in a compost bin.
 TSW explain the decay of biomass as an application to the cycling of matter
 TSW demonstrate the cycling of matter in terms of the water and carbon-oxygen.
 Water cycle: Liquid water from the ocean evaporates, condenses to form clouds, falls to
the Earth as precipitation, and returns to the ocean as runoff. (this is review)
 Carbon-Oxygen cycle: Plants convert the carbon dioxide in the atmosphere into carbon
compounds, which are used by animals that consume the plants. Oxygen is produced
by the plants and used by animals. Animals return CO2 to the atmosphere. (this is
review)
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TSW identify organic compounds that contain carbon and other elements such as H, O,
P, N and S.
TSW understand that for survival, all living things need matter, including water,
carbon, nitrogen, and phosphorous, which provide the raw materials necessary to
produce all the molecules that support life
Transfers of matter into and out of the physical environment occur at every level- for
example, when molecules from food react with oxygen captured from the environment,
the carbon dioxide and water this produced are transferred back to the environment,
and ultimately so are waste products, such as fecal material. Decomposers recycle
nutrients from dead plant or animal matter back to the soil in terrestrial environments
or to the water in aquatic environments. The atoms that make up the organisms in an
ecosystem are cycled repeatedly between the living and nonliving parts of an
ecosystem.
Understand that you are what you eat. You are made of matter that came from your
food. The body uses food for energy and as building blocks to make or repair body
tissue.
Identify that organic compounds contain carbon and other elements such as hydrogen,
phosphorus, nitrogen, or sulfur.
Physical changes include processes that change the size of a particle of a substance or
its phase, but not the identity of the substance.
Chemical changes must involve the formation of a new substance.
Signs of a chemical change are production of a gas, a color change, formation of a
precipitate and the production of heat or light. The change is not reversible.
Signs of a physical change also include heat production or absorption and a change in
the size or phase of the substance. This change is not reversible.
Mechanical digestion begins in the mouth, where your teeth break down food particles.
It continues in the stomach, where your stomach muscles squeeze and break up your
food.
7th Grade Science
Cycling of Matter Resources
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Chemical digestion of food also starts in the mouth then continues into the stomach and
small intestines. This is where food is chemically broken down into essential nutrients
keeping your body healthy and functioning normally.
Chemical digestion changes food into fuel for your body. Mechanical digestion breaks
down food particles so it is chemically digested faster. Both chemical digestion and
mechanical digestion take place in the mouth and stomach.
Large molecules are broken down during digestion.
Large molecules are composed of chains of smaller units (such as sugars) like boxcars
connected to make up a train.
Elements of compounds are rearranged due to chemical changes (this enables the
system to meet the needs of the system).
Carbohydrates, fats (lipids), proteins, vitamins and minerals.
Enzymes chemically break down large food molecules into smaller molecules that can
be absorbed and used by the body.
The student is expected to recognize how large molecules are broken down into smaller
molecules such as carbohydrates can be broken down into sugars.
A molecule is formed when two or more atoms join together. Molecules can consist of
two or more atoms of the same element or from more than one type of element.
Large molecules are made of chains of smaller units.
Our bodies take larger molecules and break them down through chemical changes
during digestion to create smaller molecules that can be absorbed by the body.
Carbohydrate chains are broken into simple sugars.
Protein chains are broken into amino acids.
Lipid chains (fats) are broken into fatty acids.
Supporting Resources
 Chew on This Lab – Student Pages (Laying the Foundation)
 Chew on This Lab – Teacher Pages
 Food web of Compost Pile
 Carbon Cycle – PowerPoint
 Carbon Cycle Worksheet
 Matter Cycles – Reading & Questions
 Organic vs Inorganic Sort
 Composting for Kids – Slide Show
 AstroBiology – The cycle of matter (teacher pages)
 AstroBiology – The cycle of matter (student handouts)
 http://www.neok12.com/Carbon-Cycle.htm
 Make a Decomposition Column
 Web Links – Cycling of Matter
 Cycling of matter - stations
 Energy Flow in Ecosystems Activity
 Composting Lab
 Science Activity: Feeding You Garden
 Composting in a Jar
 The Rotting World
 Testing for Carbohydrates
 Carbohydrates – Nutrition Information
 Organic compounds – Table and Questions
 What happens to a burger
 Organic Compounds - Powerpoint
 Comparing physical and chemical digestion
7th Grade Science
Cycling of Matter Resources
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 Digestion of Carbohydrates
 Organic Compounds for Lunch
 Teacher Instructions
 Organic Compounds
 Student Lab Procedure and Data Table
 Student Handout
 Student Handout - KEY
Content Reference Materials
 Composting Virtual Tour
 Composting – Slide Show
Assessments
 Exit Ticket – Decay of Biomass
7th Grade Science
Cycling of Matter Resources
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