Chapter #6 TRANSPORT NOTES

TRANSPORT is the INTAKE and DISTRIBUTIONof materials throughout an organism.

Transport occurs 1. Across membranes of cells

2. Within the cell itself called CYCLOSIS

3. Between parts of Multicellular Organisms

A.Structure of the Cell Membrane(FLUID MOSAIC MODEL)

The cell membrane consists of two layers of lipid molecules where protein molecules are embedded in the lipid bilayer

Phospholipid Molecule contains:a. The Head; Phosphorous

and O2b. The Tail: Carbon and

Hydrogen

B. Function of the Cell Membrane

Regulates the movements of materials that enter and exit the cell.

Also know as semi-permeable, selectively permeableCharacteristics that allow materials to move

through the membrane

Size and Electrical Charge of Molecules

Types of Transport

Passive Transport: no energy (ATP) required to move materials through the membrane

Active Transport: the cell supplies energy (ATP) to move materials through the membrane

These ideas are based on the concept of moving materials across cell membranes

DIFFUSION

1.Diffusion: random movement of molecules or ions. From an area of __HIGH____ concentration toan area of _____LOW_______ concentration.

2. Osmosis: the diffusion of water through a membrane.

EXAMPLE

The difference in concentration of molecules on each side of the membrane is called Concentration Gradient.

HIGH

LOW

Molecules pass from a region of ____LOW______concentration to a region of _____HIGH_______concentration.

THIS REQUIRES ENERGY…ATP

PINOCYTOSIS the transport of large protein moleculesor very small dissolved particles.

Occurs by the formation of POCKETS by the cell Membrane called a PINOCYTIC VESICLE. Largemolecules are transported across the cell membrane.

PHAGOCYTOSIS engulfs large chunks of undissolvedmatter. Most unicellular organisms (ameba)

See video next page

CIRCULATION is the transport of materials within cells or between parts of a multicellular organism.

THE MOVEMENT OF MATERIALS

Examples include:1. CYCLOSIS the streaming movement

of cytoplasm

2. DIFFUSION3. Use of the ENDOPLASMIC RETICULUM

See video next page

http://www.youtube.com/watch?v=PFtzs_cUddI

PLASMOLYSIS the shrinking of the cell membranedue to outward movement of water

***NEED TO KNOW***

Question: HOW DOES THE SIZE OF CELL MEMBRANES CHANGE?

Answer: TYPES OF SOLUTIONS

1. Isotonic This results in no net movement of water into or out of cells.

2. Hypertonic This results, in a net movement of water out of cells.

3. Hypotonic This results in a net movement of water into cells.

EXAMPLES

ISOTONIC SOLUTIONS

HYPOTONIC SOLUTIONS

HYPERTONIC SOLUTIONS