Transport of material within membrane bound

- Transport of Material Within Membrane-Bound Compartments, 4.6 page 114
Transport of Molecules into Cells by Endocytosis
Transport of Molecules Out of Cells by Exocytosis
- Epithelial Transport: Movement of Molecules Across Two Membranes, 4.7 page 117
Epithelial Structure
Epithelial Solute Transport
Epithelial Water Transport

Transcytosis
Level
Teacher
Objectives
- Explain the role of chemical, electrical, and electrochemical driving forces in the passive transport of
substances across a membrane, and distinguish between passive transport and active transport.
- Identify the three general factors that influence the rate at which a substance can be passively
transported across a membrane and identify the two general factors that influence the rate of active
transport.
- Identify four factors affecting the permeability of membranes to molecules that cross by simple
diffusion, and explain how and why each affects permeability.
- Compare the movement of molecules across the plasma membrane by carriers and through channels.
- Explain the distinction between primary and secondary active transport, and give examples of each.
- Explain how a difference in solute concentrations across a membrane can cause the movement of
water, and explain the distinction between the osmolarity and tonicity of a solution.
- Define endocytosis and exocytosis and explain the primary difference between these and other
mechanisms of cellular transport. Distinguish between receptor mediated endocytosis and pinocytosis.
- Explain in general terms how the polarity of epithelial cells enables them to absorb or secrete
materials.
Area
Activities
- Factors Affecting the Direction of Transport, 4.1 page 94
- What determines if passive transport or active transport will be necessary to move molecules across
the plasma membrane?
Passive Transport Versus Active Transport
- How does the transport of molecules across a membrane follow the same principles as chemical
reactions?
- What is the difference between passive and active transport?
- What is simple diffusion?
- In which of these processes do pumps play a role?
Driving Forces Acting on Molecules
- What is a driving force?
- In which direction is this force?
- How can these forces arise?
- What are the 3 types of driving forces that usually influence the movement of molecules?
Chemical Driving Forces
- When does a concentration gradient exist across a membrane?
- What kind of driving force is a concentration gradient?
- The magnitude of the chemical driving force increases as what increases? (remember, the symbol Δ,