1. Chapter 7: Membrane Structure and Function
AP Biology
Mrs. Ramon

2. Plasma Membrane Boundary that separates living cell from environment
Controls chemical traffic into and out of the cell
Selectively permeable

3. Early Models Sandwich Model, Davson and Danielli (1935)
Phospholipid bilayer between two layers of globular protein

4. Fluid Mosaic Model
Singer and Nicholson (1972)

5. Fig. 7-7 Fibers of extracellular matrix (ECM) Glyco- Carbohydrate
protein
Carbohydrate
Glycolipid
EXTRACELLULAR
SIDE OF
MEMBRANE
Figure 7.7 The detailed structure of an animal cell’s plasma membrane, in a cutaway view
Cholesterol
Microfilaments
of cytoskeleton
Peripheral
proteins
Integral
protein
CYTOPLASMIC SIDE
OF MEMBRANE

6. Passive Transport Characteristics Types
No energy is required [High]  [low]
Types
Diffusion
Facilitated Transport
Osmosis

8. Active Transport Characteristics Requires energy [low]  [high]
Transport proteins act as “pumps”

10. Moving LARGE Molecules
Exocytosis
Endocytosis
Three types:
Phagocytosis
Pinocytosis
Receptor-mediated endocytosis

11. Environment: 0.01 M sucrose “Cell” 0.01 M glucose 0.01 M fructose
Fig. 7-UN3
Environment:
0.01 M sucrose
0.01 M glucose
0.01 M fructose
“Cell”
0.03 M sucrose
0.02 M glucose

12. You should now be able to:
Define the following terms: amphipathic molecules and diffusion
Explain how membrane fluidity is influenced by temperature and membrane composition
Distinguish between the following pairs or sets of terms: peripheral and integral membrane proteins; osmosis, facilitated diffusion, and active transport; hypertonic, hypotonic, and isotonic solutions
Explain how transport proteins facilitate diffusion
Explain how large molecules are transported across a cell membrane
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