Brainteaser  What word in the English language is always spelled incorrectly?

Today you will: 1. Explain Passive Transport. 2. Explain Diffusion. 3. Explain Osmosis. 4. Explain what is meant by Facilitated Diffusion. 5. Identify The parts of a solution.

A cell has a defect that results in the loss of its ability to regulate the passage of water, food, and wastes into and out of the cell. In which of the following cell structures is this defect most likely to be located? A. ribosomes B. chloroplasts C. cell membrane D. endoplasmic reticulum REVIEW

CELLULAR TRANSPORT- DIFFUSION

About Cell Membranes 1. All cells have a cell membrane. 2. Functions: a. Controls what enters and exits the cell to maintain an internal balance called homeostasis. a. Provides protection and support for the cell. TEM picture of a real cell membrane.

About Cell Membranes (continued) 3. Structure of cell membrane Lipid Bilayer -2 layers of phospholipids a. Phosphate head is polar (water loving) b. Fatty acid tails non- polar (water fearing) c. Proteins embedded in membrane. Phospholipid Lipid Bilayer

Proteins Polar Phosphate heads love water & dissolve. Non-polar lipid tails hide from water. Carbohydrate cell markers Fluid Mosaic Model of the cell membrane

About Cell Membranes (continued)  4. Cell membranes have pores (channels) in it a. Selectively permeable: Allows some molecules in and keeps other molecules out. b. The structure helps it be selective! Pores

Types of Cellular Transport  Passive Transport cell does not use energy 1. Diffusion 2. Osmosis 3. Facilitated Diffusion  Active Transport cell does use energy 1. Protein Pumps 2. Endocytosis 3. Exocytosis high low This is gonna be hard work!! high low Weeee!! !

3 Types of Passive Transport 1. Diffusion – movement of particles from area of high concentration to an area of lower concentration. 1. Facilitative Diffusion – diffusion with the help of transport proteins (still high to low.) 1. Osmosis – (it is specific) –the diffusion of water molecules across a semi permeable membrane.

Passive Transport  cell uses NO energy  molecules move randomly  Molecules spread out from an area of high concentration to an area of lower concentration.  (High  Low)  Three types: Diffusion Osmosis Facilitated Diffusion

Passive Transport: 1. Diffusion  Diffusion: random movement of particles from an area of high concentration to an area of low concentration. (High to Low)  Diffusion continues until all molecules are evenly spaced (equilibrium is reached)-Note: molecules will still move around but stay spread out.

High Concentration Low Concentration Cell Membrane Water molecules Protein channel Transport (channel) Protein Through a  Cellular Transport from a- High Low Channel Proteins animationsChannel Proteins Passive Transport: 2. Osmosis High

3. Facilitated diffusion: diffusion of specific particles through transport proteins found in the membrane. a. Transport Proteins are specific – they “select” only certain molecules to cross the membrane. b. Transports larger or charged molecules. Osmosis (Channel Protein) Diffusio n (Lipid Bilayer) Passive Transport: 3. Facilitated Diffusion Carrier Protein AB

Solutions  A solution is a homogenous mixture of 2 or more substances in a single phase.  Solute  Solvent

Parts of a Solution  SOLUTE – the part of a solution that is being dissolved (usually the lesser amount)  SOLVENT – the part of a solution that dissolves the solute (usually the greater amount)  Solute + Solvent = Solution SolutionSoluteSolvent Hot chocolate Orange juice Salt water Chocolate milk

In a salt water solution…  Is salt the solute or the solvent?  Is water the solute or the solvent?  What does the solute do?  What does the solvent do?

Solute (salt) Solvent (water) A Salt Water Solution Animation

Solution Worksheet solute solvent solute solvent

How well did you do today? Molecules move from areas of high concentration to areas of low concentration through the process of: A. osmosis. B. diffusion. C. passive transport. D. active transport.