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Cell Biol Chapter 5 outline

Plasma Membrane and movement across membranes

I. Membranes

A) overview

1) basic structure

2) functions and other aspects

a) regulates what crosses membrane

b) intercellular communication

c) specialized junctions between cells

d) compartmentalization in eukaryotes

e) site for specific functions (photosynthesis, cellular respiration)

B) history

1) Overton

2) Langmuir

3) Gorter and Grendel = lipid bilayer

4) Singer and Nicolson = fluid mosaic model

a) mosaic aspect

b) fluid aspect

C) membrane fluidity

1) temperature

2) degree of saturation

3) fatty acid carbon chain length

4) cholesterol

D) membrane proteins

E) membrane carbohydrate

F) cell junctions

1) tight junctions

2) desmosomes

3) gap junctions

4) plasmodesmata

G) bacterial cell wall

 

II. Movement of small molecules across membranes

A) mechanisms of transport

1) simple diffusion

2) facilitated diffusion

a) carrier mediated

- channel formers - gramicidin

- ion carriers - valinomycin

3) active transport

a) simple active transport

b) symport and antiport

B) osmosis (p = RTDC)

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