Chapter Sections

Chapter Sections

Chapter Sections:

5.1 The Nature of the Plasma Membrane

5.2 Diffusion, Gradients, and Osmosis

5.3 Moving Smaller Substances In and Out

5.4 Moving Larger Substances In and Out

Student Goals:

By the end of this lecture series, students should understand these concepts:

• The basic structure and composition of plasma membranes.

• The functions of each component of the plasma membrane.

• The mechanisms by which membranes prevent passage of certain substances and permit

the passage of others, along with examples of these substances.

• What energy source is used to transport molecules across the membrane, and how that

process depends on the permeability of the membrane to those molecules.

• The three types of transport through membranes, what type of molecule each one

transports, what type of energy is required, and whether protein pores are needed.

• The mechanisms by which cells import large molecules that cannot fit through the plasma

membrane or through protein pores.

Chapter 5 Review Guide

Define all key vocabulary terms listed below:

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  1. active transport
  2. concentration gradient
  3. diffusion
  4. endocytosis
  5. exocytosis
  6. facilitated diffusion
  7. fluid-mosaic model
  8. glycocalyx
  9. hypertonic solution
  10. hypotonic solution
  11. integral protein
  12. isotonic solution
  13. osmosis
  14. passive transport
  15. peripheral protein
  16. phagocytosis
  17. phospholipid bilayer
  18. pinocytosis
  19. plasma membrane
  20. receptor protein
  21. simple diffusion
  22. transport protein

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5.1 The Nature of the Plasma Membrane

  1. Draw and describe Figure 5.1 The Plasma Membrane
  2. Describe the four main structural elements of the plasma membrane: phospholipid bilayer, cholesterol, proteins, and glycocalyx.

First Component: The Phospholipid Bilayer

  1. Draw and describe Figure 5.2 Dual Natured Lining
  2. Describe the composition of a phospholipid in terms of phosphate bearing group and fatty acids.
  3. Define hydrophobic and hydrophilic.
  4. Which portion of a phospholipid is hydrophobic? Hydrophilic?
  5. Define phospholipid bilayer and explain why it forms.
  6. Describe the two consequences of the phospholipid structure of the plasma membrane.

Second Component: Cholesterol

  1. Describe the function of cholesterol in the plasma membrane.
  2. How do cholesterol molecules react to temperature changes?

Third Component: Proteins

  1. Define and describe integral proteins.
  2. Define and describe peripheral proteins.
  3. Draw and describe Figure 5.3 Roles of Membrane Proteins.
  4. Describe the role proteins play in structural support.
  5. Describe the role of proteins in recognition.
  6. Describe the role of proteins in communication.
  7. Describe the role of proteins in transport.

Fourth Component: The Glycocalyx

  1. Describe the structure and function of glycocalyx.

The Fluid-Mosaic Membrane Model

  1. Define plasma membrane.
  2. Define fluid mosaic model.

5.2 Diffusion, Gradients, and Osmosis

  1. Describe how substances move in terms of concentration.
  2. Draw and describe Figure 5.4 From Concentrated to Dispersed.

Random Movement and Even Distribution

  1. Describe the random movement and motion of molecules.
  2. Define diffusion.
  3. Define concentration gradient.

Diffusion through Membranes

  1. Define Osmosis.
  2. Draw and describe Figure 5.5 Osmosis in Action

The Plasma Membrane as a Semipermeable Membrane

  1. Define semipermeable. What substances is the plasma membrane permeable to? What substances is the membrane not permeable to?

Osmosis and Cell Environments

  1. Define hypertonic solution.
  2. Define isotonic.
  3. Define hypotonic solution.
  4. Draw and describe Figure 5.6 Osmosis in Cells.

5.3 Moving Smaller Substances In and Out

  1. Compare and contrast active and passive transport.
  2. Draw and describe Figure 5.7 Transport through the Plasma Membrane

Passive Transport: Simple Diffusion

  1. Define simple diffusion.
  2. What types of substances can move through the membrane by simple diffusion?

Passive Transport: Facilitated Diffusion: Help from Proteins

  1. Define facilitated diffusion.
  2. What types of substances move through the membrane by facilitated diffusion?
  3. Draw and describe Figure 5.8 Facilitated Diffusion.

Active Transport: The Sodium-Potassium Pump

  1. How does the sodium-potassium pump help to maintain homeostasis within a cell?
  2. Draw and describe Figure 5.9 The Sodium Potassium Pump.

5.4 Moving Larger Substances In and Out

Movement Out: Exocytosis

  1. Define exocytosis.
  2. Draw and describe Figure 5.10 Movement Out of the Cell.

Movement In: Endocytosis

  1. Define endocytosis.

Pinocytosis

  1. Define pinocytosis.
  2. Draw and describe Figure 5.11 (a)—Two Ways to Get Relatively Large Materials into the Cell.

Phagocytosis

  1. Define phagocytosis.
  2. Draw and describe Figure 5.11 (b)—Two Ways to Get Relatively Large Materials into the Cell.

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