LAB: Organic Molecule – Lipid
Learning Objective:
1. Lipids are one of the 4 organic molecules that occur in all living things.
2. All membrane-bound organelles are made from Lipids (Cell Membrane, Nuclear Membrane, inner
and outer Mitochondrial Membrane, etc)
3. Membranes come in various shapes depending on function and have proteins embedded in them to
facilitate other molecules to pass through them.
4. Lipids are made up of closely related polar monomers called phospholipids that form a Lipid
Bilayer.
a. Phospholipids have Hydrophilic heads.
b. Phospholipids have Hydrophobic tails made of fatty acids.
Discussion Points:
1. A cell is enclosed, or defined by a membrane.
2. A wide variety of proteins are located in and around membranes. These proteins can associate with
membranes in a variety of ways.
3. Integral proteins extend through one or both layers of the phospholipid bilayer.
4. Some proteins are attached to lipid molecules which anchor them to the membrane.
5. Receptor proteins transmit signals across a membrane.
6. Transporter and channel proteins form pores through the membrane that can be opened and closed to
allow specific molecules to pass through.
7. Membranes also organize the interior of a cell. Cell organelles are defined by membranes.
8. Membranes form spontaneously.
Standards:
CA State Standards:
Cell Biology
1. The fundamental life processes of plants and animals depend on a variety of chemical reactions that
occur in specialized areas of the organism’s cells. As a basis for understanding this concept:
a. Students know cells are enclosed within semipermeable membranes that regulate their interaction with
their surroundings.
h. Students know most macromolecules (polysaccharides, nucleic acids, proteins, lipids) in cells and
organisms are synthesized from a small collection of simple precursors.
Common Core Standards:
HS-LS1-6.
Construct and revise an explanation based on evidence for how carbon, hydrogen, and oxygen
from sugar molecules may combine with other elements to form amino acids and/or other large
carbon-based molecules.
Lesson modified by Angel Ireys, High School Biology teacher – Valley Academy of Arts and Science
from - http://learn.genetics.utah.edu © 2008 University of Utah
Background Info:
Cell membranes are made of phospholipid molecules that arrange themselves into two rows called a bilayer. Proteins are embedded in the phospholipid bilayer, through one or both layers. These proteins help
other molecules cross the membrane and perform a variety of other functions. Create a model of a small
section of cell membrane by following the instructions below.
Lipids
Functions:
1. Store useable energy
2. Create cell structures specifically cell membranes and any organelle with a membrane
Monomer – Phospholipid
Polymer – Cell membrane and other structures
Lesson modified by Angel Ireys, High School Biology teacher – Valley Academy of Arts and Science
from - http://learn.genetics.utah.edu © 2008 University of Utah
LAB: Organic Molecule 3-D Model – Lipid
Materials per set of 2 students:
1. A kit of 3-D phospholipid molelules.
a. (24) Round balls = Hydrophilic Heads; (192) Springs = Hydropobic tails.
2. Various shaped protein models to embed into the molecule as transport channels.
Student Directions:
1. Acquire a box of phospholipid constituents (parts) and connector pieces. Identify the parts:
hydrophilic phosphate heads, hydrophobic lipid tails.
2. Assemble the phospholipid bilayer connecting the heads and tails of the phospholipids. Include the
pieces that represent proteins into the model as you build it.
3. Form a 3-D shape by joining the protein sides and tops together and connect them in to place.
4. Once assembled, notice how the structure is secure but still pliable.
Lesson modified by Angel Ireys, High School Biology teacher – Valley Academy of Arts and Science
from - http://learn.genetics.utah.edu © 2008 University of Utah