UNIT 3: CELLULAR BIOLOGY – STRUCTURE
RELATED TO FUNCTION
3B: Cell Membrane & Transport
Roadmap for the year:
Unit 1: Interconnectedness of Life
Unit 2: Ecological Biochemistry
Unit 3: Cellular Biology: Structure Leads to
Function
 3A Origins of Life
 3B Cell Membrane and Transport
 3C Cell Structure and Function
Unit 4: DNA Structure and Cellular Reproduction
Unit 5: Gene Expression and Inheritance
Unit 6: Evolution and Classification of Living Things
Unit 7: Biotechnology, Human Biology, and Disease
Themes for the year:
How does this unit
contribute to your
understanding of the
following themes?
 Life on Earth has
various Levels of
Organization
 The Structure of
Living Things leads
to their Function
The Big Picture for Unit 3…
Evidence supports that earth and the organisms that inhabit it have changed greatly over time. The
diversity of life is the result of ongoing evolutionary change. Species alive today have evolved from ancient
common ancestors. Cells are the basic units of structure and function of all living things. Cells in a
multicellular organism are interdependent upon each other. Cells are dynamic and constantly work towards
maintaining homeostasis. Processes that occur at the cellular level provide the energy and basic structure
organisms need to survive.
1. How did life on Earth begin, and how has it changed over time?
2. How do cell structures enable a cell to carry out basic life processes?
3. How does a cell maintain homeostasis both within itself and as part of a multicellular
organism?
4. How do organisms obtain the energy and they need to survive?
5. How do we know that all living things are made of cells?
6. Why aren’t all cells identical?
Suggested Resources…
Homework Assignments
Classwork Assignments
Laboratory Activities
Note Packet
Textbook Chapter 7 (Section 7.3)
Online Textbook Activities: Interactive Art (Passive Transport, Diffusion, Osmosis) and Art in Motion (Protein Pumps,
Endocytosis, Exocytosis)
Directions: Below are check lists of things you should know and things you should
be able to do by the end of the unit. Use this tool to help you prepare for the unit
assessment.
By the conclusion of this unit, you should know
the following:
1. A cell membrane is a selectively permeable
boundary that helps cells maintain homeostasis
by regulating what enters/leaves cells.
2. Specialized molecules like transport proteins
and cholesterol can be found in the cell
membrane.
3. Substances such as oxygen and basic nutrients
must be able to enter cells; waste products
must be able to exit cells through the cell
membrane.
4. Both active and passive transport mechanisms
allow substances to enter/leave cells according
to concentration gradients and/or the cell’s
needs.
5. Passive transport (including diffusion and
osmosis) is the movement of materials across
the cell membrane without cellular energy.
6. The movement of materials against a
concentration difference is known as active
transport. Active transport requires energy.
7. Water moves into or out of cells by osmosis.
8. Water is a polar molecule. Therefore, it is able
to form multiple hydrogen bonds, which account
for many of its special properties.
9. Some covalent bonds don’t share electrons
equally and result in molecules which have
unequal charge distribution (polar covalent
bonds).
10. Water’s special properties allow it to act as a
solvent in which solutions can form. Some
molecules (polar) dissolve and some (ionic
compounds) dissociate.
A solution is a mixture consisting of a solute
uniformly dissolved in a solvent. The solvent
is identified as that component which makes
up the bulk of the solution.
By the conclusion of this unit, you should
be able to do the following:
1. Describe the different types of biological
molecules and their functions that make up
the cell membrane.
2. Give examples of substances that are
normally moved across cell membranes.
3. Relate the structure of the cell membrane to
its function in selective permeability.
4. Distinguish between passive and active
transport.
5. Compare and contrast passive transport
(diffusion, osmosis, facilitated diffusion) with
active transport (including molecular active
transport and endocytosis/exocytosis).
6. Solve problems involving the movement of
solutes and/or water across selectively
permeable membranes, along their
concentration gradients, including the
identification of hypertonic, hypotonic, or
isotonic solutions.
7. Predict what type of transport would be
expected for the movement of certain
molecules into/out of cells.
8. Infer how the structure (polarity) of water
contributes to its unique properties and its
role as a solvent.
9. Justify how water acts as the ‘universal
solvent’ in biological systems.
Cell Membrane & Transport Key Terms
Words found in the textbook:
1) Diffusion:
2) Facilitated Diffusion :
3) Osmosis :
4) Isotonic :
5) Hypertonic :
6) Hypotonic :
7) Active Transport (pg. 212) :
8) Endocytosis (pg. 213) :
9)
Exocytosis (pg. 213) :
10) Homeostasis :
11) Selectively Permeable :
12) Lipid Bilayer :
13) Solute :
14) Solvent :
15) Cell membrane: