Chapter 8 Membrane Structure and Function p. 138

Membrane Structure p. 138

Amphipathic molecule

 

 

Fluid Mosaic Model

 

 

 

Membranes are Fluid p. 141

What types of reactions hold a membrane together?

 

 

What keeps membrane fluidity, even at lower temperatures?

 

 

 

 

 

Membranes are mosaics of structure and function p. 142

Integral Proteins

 

 

Peripheral proteins

 

 

Figure 8.6 p. 142

 

 

What is meant by sidedness of the plasma membrane?

Figure 8.8 p. 143

 

 

 

 

What does extracellular side mean?

 

 

What does cytoplasmic side mean?

 

 

 

What does cell-cell recognition mean? Why is it important? How does a cell recognize a cell?

 

 

Oligosaccharides

 

 

Glycoproteins

 

 

Figure 8.9 p. 144 Some Functions of membrane proteins

 

 

 

Traffic Across membranes p. 144

 

A membrane’s molecular organization results in selective permeability

What are the types of molecules that move across the membrane with ease?

What are the types of molecules that difficulty moving across the plasma membrane?

 

Transport proteins p. 145

What is the role of transport proteins?

Explain selective permeability

 

Passive Transport is diffusion across a membrane p. 145

Diffusion

Concentration Gradient

Does the concentration of one substance impact the movement of other substances down a concentration gradient?

 

Figure 8.10 p. 145

Passive transport

 

 

Why can water move freely across a selectively permeable membrane?

 

Osmosis is the passive transport of water p. 146

Hypertonic

Hypotonic

Isotonic

How does molecule size impact movement across a selectively permeable membrane?

 

Figure 8.11 Osmosis p. 146

You must be able to determine the movement of water and other substances across a membrane.

Osmosis

 

 

Cell Survival depends on balancing water uptake and loss p. 146

What will happen to an animal cell placed in an isotonic solution? Why?

What will happen to an animal cell placed in a hypertonic solution? Why?

What will happen to an animal cell placed in a hypotonic solution? Why? 

Figure 8.12 p. 147

Lyse

Osmoregulation

Contractile vacuole

Figure 8.13 p. 147

What will happen to a plant cell placed in an isotonic solution? Why?

What will happen to a plant cell placed in a hypertonic solution? Why?

What will happen to a plant cell placed in a hypotonic solution? Why?

Turgid

Flaccid

Plasmolysis

 

Specific proteins facilitate the passive transport of water and selected solutes p. 147

Facilitated Diffusion

A transport protein has many of the properties of an enzyme. Explain

Channel proteins

Aquaporins

Gated channels 

Figure 8.14 p. 148

Active transport is the pumping of solutes against their gradients p. 148

Active transport

Why important?

Figure 8.15 p. 149

Sodium Potassium pumps

 

 

Some ion pumps generate voltage across membranes p. 149

What causes membrane voltage?

Membrane potential

Cations

Anions

Electrochemical gradient

Figure 8.17 p. 150

Sodium potassium pump Figure 8.15

Electrogenic pump

Figure 8.17 p. 150

Proton pump

 

In cotransport, a membrane protein couple the transport of two solutes p. 150

Cotransport

Figure 8.18 p. 151

 

 

Exocytosis and Endocytosis transport large molecules p. 151

Exocytosis

Example

 

Endocytosis

3 Types of Endocytosis

Phagocytosis

 

 

Pinocytosis

 

 

Receptor-mediated Endocytosis

Coated pits

 

Ligands

 

LDL

Causes of high cholesterol

 

Figure 8.19 p. 152

 

Self-Quiz p. 153 1-18