“Materials move across the cell’s membranes” Section 2.3

Do NOW What is passive transport? What are 2 examples of passive transport? Explain what happens when you put a sugar cube in your tea in regards to diffusion.

Objectives To understand how the process of Osmosis works. To explain the different types of solutions To compare and contrast endocytosis vs. exocytosis.

Do Now What is the purpose of the cell membrane in a cell? What goes in and out of our cells? Why are our membranes important?

Objectives To explain the different functions of the macromolecules in the plasma membrane. To understand the process of diffusion. To compare and contrast active and passive transport.

Membranes “Fluid Mosaic Model”

Membrane Components Phospholipids: Gives the general structure of the membrane

Proteins: allow bigger substances to pass through, also provide structure

Cholesterol: helps maintain structure of phospholipidssticking

Carbohydrates: receptors that send and receive signals.

Simulation Activity Everybody Stand up!!! Lets make a membrane out of the desks. I need 4 volunteers (1-H2O, 3-Glucose)

Types of Transport Passive Transport Active Transport Diffusion Facilitated diffusion Osmosis Active Transport Vesicular Transport Endocytosis Exocytosis

Passive Transport Do NOT require energy Go from an area of high concentration to an area of low concentration “high to low” “Go with the flow”

3 Types of Passive Transport Diffusion Facilitated Diffusion Osmosis

Diffusion Molecules move from a high concentration to a low concentration to create DYNAMIC EQUILIBRIUM EQUILIBRIUM.

Facilitated Diffusion the molecules need a “helper” or “facilitator” to allow them to cross the membrane when they are too big.

What effects the rate? Heat- higher temp increases rate State of Matter Solid- slow Liquid- faster Gas- fastest Size and Concentration Bigger= slower More concentration = faster

Perfume Demo

Food Coloring Demo

Osmosis The flow of WATER from a high concentration to a low concentration Occurs based on the types of solutions you are working with.

Active Transport Uses energy to move materials through a membrane Example: removing salt from your body Kidneys filter wastes from your blood by active transport.

Vesicular Transport ENDOcytosis – “in” EXOcytosis – “out” Large bits of materials captured within a pocket of the membrane. Pocket breaks off and forms a package that moves into the cell Used to fight bacteria and viruses off be absorbing them! Uses to get rid of large materials inside. Package moves to the cell membrane and the material is expelled Used to flush out wastes, proteins, or hormones made by cell.

Solution Solution: A mixture in which you cannot separate the components (ex: Kool aid) Solute: the substance being dissolved Ex: kool aid powder Solvent: The substance doing the dissolving Ex: water “OH YEAHHHHH”

Solutions Solutions can be… Isotonic Hypertonic hypotonic

Isotonic Solutions Plant Cell Blood Cell Same amount of solute inside the membrane as there is outside. Cell in this solution: Normal ☺ Plant Cell Blood Cell 11,397x

HYPERtonic Solutions More solute, less solvent Cell in this solution:shrinks/shrivels “Plasmolysis” “Crenates”

HYPOtonic Solutions Less solute, more solvent Effect: cell swells or bursts!

High or low Solute? Cell in ________ Solution

A salt water fish is put into a freshwater aquarium. Scenario 1 A salt water fish is put into a freshwater aquarium. What type of solution is the freshwater? What is going to happen to the cells of the fish?

Scenario 2 A patient is given an IV, which contains the perfect balance of glucose What type of solution is in the IV? What is going to happen to the cells of the human?

Scenario 3 Your garden is infested with slugs so you go around pouring salt on them What type of solution is this salt? What is going to happen to the cells of the slug? (don’t do this to the poor slugs ☹)

Practice By yourself or with a partner (anyone), work on the diffusion problems. First try to do this by yourself, then verify your answers with a partner. Try to help each other. If you are confused, raise your hand and I will come help you!! If you finish early, try to answer the “Think about it” questions on my desk! If you don’t finish, please finish it for homework.