A chef peels several cloves of garlic for use in a recipe. The chef puts the peeled garlic in a plastic bag and places the bag in the refrigerator. Several hours later, the chef opens the refrigerator and observes a strong smell of garlic. Through what process were molecules able to pass through the plastic bag? Aosmosis Bdiffusion Ccell division Dphotosynthesis Bellwork Answer on the sheet of notebook paper you used yesterday!

Objectives Explain how materials move through simple diffusion. (SPI ) Students will be able to analyze how plant and animal cells are organized to carry on the processes of life.

Diffusion Lab Questions- Answer in your notebook below your observations. 1. The plastic bag is semipermeable to which substance? ​ 2.Why did the iodine enter the bag? ​ 3.Why didn’t the starch enter the beaker? ​ 4.How is the plastic bag like the cell membrane? ​ 5.What is the definition of the word “diffusion”?

Question...Elbow Partner In diffusion and osmosis, why do the particles move from areas that are more crowded to areas that are less crowded? For a cell to survive, the amount of molecules need to be the same on both sides of the cell membrane. If the cell does not pump out all of its extras to even things out, this could be very bad. The cell can swell up and explode. Listen to this…

48. Diffusion & Osmosis Notes What is Diffusion? The movement of particles from regions or areas of HIGH concentration (crowded) to areas of LOW concentration (less crowded) is called DIFFUSION. Look at Figure 1 on pg. 78! The dye moved from an area of high concentration and spread to the area of low concentration. Why? Ex: when oxygen diffuses into the cell and carbon dioxide diffuses out.

Equilibrium Sugar molecules, initially in a high concentration at the bottom of a beaker, will move about randomly through diffusion and eventually reach equilibrium. At equilibrium the sugar concentration will be the same throughout the beaker. Diffusion occurs naturally because of the kinetic energy the molecules possess.

Diffusion of Water Diffusion also happens with and between living cells. The cells of organisms are surrounded by and filled with fluids that are made mostly of WATER. The diffusion of water through a SEMI-PERMEABLE (partially allows things through) membrane is so important that it has been given a special name- OSMOSIS. Look at Figure 2 on pg. 79!

Moving Small Particles In a cell, the movement of particles across a cell membrane WITHOUT the use of energy by the cell is called PASSIVE TRANSPORT. During passive transport, particles move from an area of HIGH concentration to an area of LOW concentration. Examples:DIFFUSION & OSMOSIS A process of transporting particles that requires the cell to use energy is called ACTIVE TRANSPORT. Active transport usually involves the movement of particles from an area of LOW concentration to an area of HIGH. This happens a lot in neurons. The membrane proteins are constantly pumping ions (atoms or molecules that have a + or – electrical charge) in and out to get the membrane of the neuron ready to transmit electrical impulses.

Moving Large Particles The active transport by which a cell surrounds a large particle, such as a large PROTEIN, and encloses the particle in a vesicle to bring the particle into the cell is called ENDOCYTOSIS. Vesicles are SACS formed from pieces of cell membrane. Ex: when iron diffuses into the cell using active transport because the iron molecules are too large. When large particles, such as WASTE, leave the cell, the cell uses an active transport called EXOCYTOSIS. During exocytosis, a vesicle forms around the large particle, carries the particle to the cell membrane, fuses with the cell membrane, and releases the particle outside of the cell.

What do you know? Describe how each of the following materials would get through the cell membrane and into a cell: 1.Pure water 2.Sugar entering a cell that already contains a high concentration of particles 3.Sugar entering a cell that has a low concentration of particles 4.A protein

What do you know? Answers Describe how each of the following materials would get through the cell membrane and into a cell: 1.Pure water Osmosis 2.Sugar entering a cell that already contains a high concentration of particles Active Transport 3.Sugar entering a cell that has a low concentration of particles Passive Transport 4.A protein Endocytosis

Name Tag Activity Objective: Balance the “particles” through diffusion and osmosis. 1 st Time- Only the glucose molecules can move. 2 nd Time- Only the water molecules can move.

Exit Post-It Describe the difference between Endocytosis and Exocytosis