Download Grading the Explanations Tool for Decomposers Biosynthesis

Grading the Explanations Tool for Decomposers Biosynthesis:
How does a cell in a decomposer use food to grow and divide?
This grading worksheet does not have an Activity number in the title because it can be used to grade all
Explanation Tools for biosynthesis in this Unit.
This worksheet has “grading” in the title because at this point, students can be held accountable for correct
answers. Level 4 (correct) responses to the questions are in blue bold italics below. There are also
comments about common Level 2 and Level 3 responses to help you with grading and making decisions about
what to emphasize in future lessons.
Bread mold’s cells grow larger and divide as they use small organic molecules to make large organic
molecules such as proteins and fats. Answer the Three Questions to explain how a cell in the mold’s mycelium
can grow and divide.
The Movement Question: Zooming in to trace matter
1. Mold: Draw arrows that show how molecules with
carbon atoms move into and through the bread mold so
that a cell in the mold’s mycelium gets the food it needs
to grow larger and divide. Label the arrows with the
names of molecules the carbon atoms are in.
Level 4: Polymers (large organic molecules) such as
proteins, fats/lipids and/or carbohydrates, in the bread
are broken down to monomers. Arrows labeled with
these monomers (small organic molecules) such as
amino acids, sugars, fatty acids and glycerol show them
entering the fungus and traveling through the hyphae to
a particular cell.
2. Cell: Draw arrows that show how molecules with
carbon move into, and through the mold’s cell when it
grows larger and divides. Label the arrows with the
names of molecules the carbon atoms are in.
Level 4: Arrows labeled with monomers such as amino
acids, sugars, fatty acids and glycerol go into the cell.
What is the name of this chemical change that allows the
mold’s cell to grow and divide?
Biosynthesis
The Carbon Question: How atoms are rearranged into new molecules
What molecules are carbon atoms in before the
What molecules are carbon atoms in after the chemical
chemical change?
change?
Level 4: amino acids, glucose, fatty acids,
Level 4: proteins, fats/lipids, and/or starch
glycerol
Chemical
What other molecules are produced?
Change
What other molecules are needed?
Level 4: water
Level 4: none
Decomposers Unit
Carbon: Transformations in Matter and Energy
Environmental Literacy Project
1
Michigan State University
The Energy Question: How energy is transformed
What forms of energy are needed for this chemical
What forms of energy are produced by this chemical
change?
change?
Level 4: Chemical energy
Level 4: Chemical energy
Where does the energy come from?
Level 4: C-C and C-H bonds in amino
acids, sugars, fatty acids and glycerol.
Energy
Transformation
Where does the energy go or stay after the
change?
Level 4: C-C and C-H bonds in the
protein, fat/lipids and/or carbohydrates.
Remember: Atoms last forever (so you can arrange atoms into new molecules, but can’t add or subtract atoms).
Energy lasts forever (so you can change forms of energy, but energy units can’t appear or go away).
Use the process tool to help guide your written explanation. Answer all Three Questions in your explanation.
Question: How does cell in bread mold use food to grow larger and divide? (Answer on the back).
Level 4: Small organic molecules (monomers) such as amino acids, sugars, fatty acids and glycerol
in a cell are combined together to make new large organic molecules (polymers), such as
carbohydrates, fats and proteins. These large organic molecules are what cells are made of. As the
cells make more and more large molecules, they get bigger and bigger. Once they get big enough,
they divide. Water is produced when the larger molecules are made from smaller ones. These
polymers (large organic molecules) have chemical energy stored in the C-C and C-H bonds,
because the C-C and C-H bonds of the monomers (small organic molecules) are still there. This
process is called biosynthesis.
Level 2 and 3 responses may describe cells using food molecules to grow but focus on the food being used for
energy in order for the cell to grow and divide. Level 3 responses might include more detail equating
biosynthesis to cellular respiration than Level 2 responses.
Decomposers Unit
Carbon: Transformations in Matter and Energy
Environmental Literacy Project
2
Michigan State University