Chapter 7-3 Notes Part 2 Types of Transport

TRANSPORT CAN BE EITHER

Passive On top of the hill DOES NOT REQUIRE ENERGY!!! Movement of molecules from areas of high concentration to areas of lower concentration. DOES NOT REQUIRE ENERGY!!! DRAW high low Weeee!!!

OR

This is gonna be hard work!! Active Bottom of the hill Movement of molecules from areas of low concentration to areas of high concentration. REQUIRES ENERGY! high low This is gonna be hard work!! DRAW

Animations of Active Transport & Passive Transport Types of Passive Transport cell does not use energy Diffusion Facilitated Diffusion Osmosis Types of Active Transport cell uses energy Protein Pumps Endocytosis Exocytosis

All 3 types of PASSIVE transport occur until equilibrium is reached. when the concentration of a solute is the same throughout a closed system. (i.e. Inside and outside of a cell.)

Three Types of Passive Transport Defined

1. Diffusion: movement of molecules FROM areas of HIGH concentration TO areas of LOW concentration through the lipid bilayer. Examples: Alcohol, CO2, O2

DIFFUSION ANIMATION

Facilitated diffusion (Channel Protein) Diffusion (Lipid Bilayer) Diffusion of specific particles through transport proteins found in the cell membrane Example:Glucose Transport Proteins are specific – they “select” only certain molecules to cross the membrane Transports molecules that are large or insoluble in lipids. Facilitated diffusion (Channel Protein) Diffusion (Lipid Bilayer) Carrier Protein http://bio.winona.edu/berg/Free.htm

3. Osmosis Osmosis animation 3.Osmosis: diffusion of WATER through a selectively permeable membrane. a. Water moves from high concentration of (H2O)to low concentration(of H2O) Water moves freely through special pores. Solute (green) soluble in lipids.

Ch 7-3 Notes Part 3

Effects of Osmosis on Life Cells can not control the movement of water (Osmosis). ii. If too much water moves into the cell it can burst (die). If too much water moves out it can shrivel up (die).

HOW DO SOLUTIONS AFFECT OSMOSIS???

There are three types of solutions a cell can be in: The prefixes of the solutions describe the amount of solute in the solution compared to in the cell. Hypotonic- Hypertonic- Isotonic - Below , under Above, more than, higher Equal to

Hypotonic Solution Has a lower concentration of solutes and a higher concentration of water than inside the cell. (Low solute; High water) Result: Water moves from the solution into the cell) Osmotic pressure increases and causes the cell to grow until equilibrium is reached or the cell bursts. Hint: HYPO=HIPPO(grow)

Osmosis Animations for isotonic, hypertonic, and hypotonic solutions Hypertonic Solution Has a higher concentration of solutes and a lower concentration of water than inside the cell. (High solute; Low water) Result: Water moves out of the cell into the solution: Cell shrinks/shrivels.

Isotonic Solution(Iso=Equal) Isotonic: The concentration of solutes and water in the solution is equal to the concentration of solutes and water inside the cell. Result: Water moves equally in both directions (Dynamic Equilibrium) and the cell remains same size!

2 3 1 What type of solution are these cells in? Hypertonic Isotonic TOO MUCH OSMOTIC PRESSURE!!! 2 3 1 Hypertonic Isotonic Hypotonic *Which of these solutions do you think is used in an IV?

How Organisms Deal with Osmotic Pressure 1. A protist, like paramecium, has contractile vacuoles that collect water flowing in and pump it out to prevent them from over- expanding. Contractile Vacuole:

2. Bacteria and plants have cell walls that keep the membrane from bursting when osmotic pressure increases.

3. Animal cells are bathed in blood 3. Animal cells are bathed in blood. Kidneys keep the blood isotonic by removing excess salt and water.

Part 4: Active Transport Ch 7-3 Notes Part 4: Active Transport

IV. Active Transport (Low  High) A. Requires energy (going up hill) B. Actively moves molecules to where they are needed C. Movement from an area of low concentration to an area of high concentration (remember: up the hill) (Low  High)

D. Three Types of Active Transport Protein Pumps Endocytosis Exocytosis

D. 3 Types of Active Transport Sodium Potassium Pumps (Active Transport using proteins) Protein Pumps –Require energy transport molecules across membrane. Example: Ions such as Na+ and K+ in Sodium / Potassium Pumps, which are important in nerve responses. Protein changes shape to move molecules: this requires energy!

Types of Active Transport Continued. 2. Endocytosis: taking bulky material into a cell a. Uses energy b. Cell membrane folds in around food particle “cell eating” c. forms food vacuole & digests food d. This is how white blood cells eat bacteria!

Types of Active Transport 3. Exocytosis: Forces material out of cell in bulk a. membrane surrounding the material fuses with cell membrane b. Cell changes shape – requires energy EX: Hormones or wastes being released from the cell Endocytosis & Exocytosis animations Exocytosis

Simple Diffusion Animation http://bio.winona.edu/berg/Free.htm