Unit: Organic Molecules
Learning Focus: 3.1
Time: 90 minutes
Defining Success
OBJECTIVE: What will your students be able to do by the end of class?
9A – Compare the structures and functions of different types of biomolecules such as proteins,
carbohydrates, lipids, and nucleic acids.
ASSESSMENT: How will you know concretely that
all of your students have mastered the objective?
Students will be able to identify the structure of
proteins, carbohydrates and lipids, and the elements
that make up each.
Lesson Cycle
Students will be able to relate the structure of the
molecules to their functions within a cell.
KEY POINTS: What three to five main ideas
or steps will you emphasize in your lesson?
May also include key questions to ask during
instruction.
What are the functions of proteins, lipids,
carbohydrates, and nucleic acids?
What are examples of proteins, lipids,
carbohydrates, and nucleic acids?
Describe foods that each of the 4
biomolecules is found in.
How does the structure of each biomolecule
relate to its function?
ENGAGE:
Given a few foods in containers with nutrition labels, students investigate the
different amounts of nutrients (fats/lipids, carbohydrates and proteins) found in
each. Have students write observations in their lab notebooks of the nutrition
information for their food item, paying particular attention to fats, carbohydrates
and protein content. This allows students to make a personal connection to the
biomolecules.
MATERIALS
Various food
items or boxes
with nutrition
labels: chips,
pasta, cheese,
milk, tuna, etc.
EXPLORE:
Students investigate (or build, depending on time) models of each of the
biomolecules. Which elements are found in each of the biomolecules? Which of
these molecules contains an element not found in the others? Which element is
it? Compare the shapes of the different molecules. Which one do you think stores
the most energy? Why?
Student lab
notebook
Molecular
model kit
EXPLAIN:
Teacher leads a discussion using the models of each biomolecule. Students
record the name of each biomolecule, its function, examples of the biomolecule,
and foods the molecule is found in. Pay specific attention to the number of bonds
found in lipids, which illustrates the amount of energy that can be stored. Note that
carbohydrates are similar to lipids in composition, but much smaller molecules.
Make sure students note that proteins contain nitrogen. The focus of this Explain
should be on lipids, carbohydrates and proteins (nucleic acids have been studied
in detail in previous lessons). Use a diagram of the cell membrane to illustrate
where each of these molecules are located, referring back to the previous lessons
on the cell and its organelles.
Molecular
model kit;
diagrams of
biomolecules;
diagrams of cell
membrane and
cell structure.
ELABORATE:
Students work in small groups to create a graphic organizer illustrating the
characteristics of each biomolecule. For each biomolecule the following
information must be included:
 Structure of the biomolecule
 Unique characteristics of each biomolecule
 At least two functions of the biomolecule (one general and one specific to cell
function)
 Locations (at least two) in the cell where the biomolecule is found and its
corresponding function
 How this biomolecule is similar to another of the biomolecules and how it is
different (not necessarily to the same biomolecule)
EVALUATE:
Students work individually to complete the “Understanding Biomolecules” table,
without using their notes or posters (unless modifications are needed).
Chart paper
Markers
Notes and
textbook or
other source
information
Understanding
Biomolecules
Sheet