Chapter #6 TRANSPORT NOTES TRANSPORT is the INTAKE and DISTRIBUTION of 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 O 2 b. 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 permeable Characteristics 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 to an 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 molecules or very small dissolved particles. Occurs by the formation of POCKETS by the cell Membrane called a PINOCYTIC VESICLE. Large molecules are transported across the cell membrane.

PHAGOCYTOSIS engulfs large chunks of undissolved matter. 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. DIFFUSION 3. Use of the ENDOPLASMIC RETICULUM See video next page

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PLASMOLYSIS the shrinking of the cell membrane due 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