Biology 12Mrs. Knowles

Plasma membrane: Chapter 4

By the end of this chapter, you should be able to:

Describe the fluid-mosaic model of the plasma membrane Identify the function of the five types of membrane proteins and cholesterol Differentiate between the 5 methods of transport in terms of energy usage, direction,

requirements, molecules moved, and process Describe effects on cells when placed in solutions of varying tonicity

Fluid-mosaic model

Fluid:

Mosaic:

Phospholipid bilayer:

Proteins:

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Cholesterol:

Types of plasma membrane proteins:

1. Channel protein

2. Carrier protein

3. Receptor protein

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4. Enzymatic protein

5. Cell recognition protein

Permeability

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Selectively permeable

Transport

Concentration gradient:

PASSIVE TRANSPORT

Passive transport

TYPES:

Active transport

REQUIRES:

TYPES:

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TYPE 1: Diffusion

DIRECTION:

REQUIREMENT:

EXAMPLES:

OSMOSIS

Osmotic pressure

Tonicity:

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I. Isotonic solution

ii. Hypotonic solution

iii. Hypertonic solution

TYPE 2: Facilitated transport

Animal cells: Plant cells:

Animal cells: Plant cells:

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DIRECTION:

REQUIREMENT:

Carrier proteins:

EXAMPLES:

ACTIVE TRANSPORT

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TYPE 1: Active transport

DIRECTION:

REQUIREMENT:

EXAMPLES:

Na+/K+ pump

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The molecules that are too large for carrier proteins....

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TYPE 2: exocytosis

DIRECTION:

REQUIREMENT:

EXAMPLES:

TYPE 3: endocytosis

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DIRECTION:

REQUIREMENT:

EXAMPLES:

a. Phagocytosis

b. Pinocytosis

c. Receptor-mediated endocytosis

Biology 12Mrs. Knowles