30 How did we observe diffusion in the

#30 How did we observe diffusion in the State Lab? Warm up How did we use indicators in the Diffusion Lab? Find your Diffusion Lab

#30 How did we observe diffusion in the State Lab? Diffusion Through a Membrane DIN – Turn your lab over to the back. Write down a few sentences about what is happening in the video AND why it is happening. EGG VIDEO

#30 How did we observe diffusion in the State Lab? Review of the Cell Membrane • The Cell Membrane is Semi. Permeable or Selectively Permeable • Small molecules (like glucose) are able to pass through the membrane while large molecules (like starch) cannot pass through

#30 How did we observe diffusion in the State Lab? Diffusion Through A Membrane glucose molecule PART of a starch molecule

#30 How did we observe diffusion in the State Lab? What we used for the lab • Dialysis Tubing – used to make a “cell” that will allow small particles to pass through and not large particles • Glucose Solution – a simple sugar made of one small molecule of sugar • Starch Solution – a complex carbohydrate made of hundreds of simple sugars bonded together

#30 How did we observe diffusion in the State Lab? Indicators • Starch Indicator Solution – (Iodine), a really small molecule (It’s only 2 atoms big) • Glucose Indicator Solution – Benedict’s solution

#30 How did we observe diffusion in the State Lab? Initial Cell “Cell” with glucose and starch Water and starch indicator solution

#30 How did we observe diffusion in the State Lab? The Final Cell The water stayed amber The cell turned blue-black Water from outside the cell tested positive for glucose

#30 How did we observe diffusion in the State Lab? Quick Video of Iodine (Starch Indicator Solution) diffusing INTO the Cell!

#30 How did we observe diffusion in the State Lab? What Happened? ? • Glucose was small enough to pass through the membrane so it ended up in the water outside the cell • Starch was too big to pass through the membrane so it didn’t get out of the cell • Iodine (starch indicator solution) was small enough to pass through the membrane so it ended up in the cell turning the cell blue-black

#30 How did we observe diffusion in the State Lab? Diffusion Through a Membrane

#30 How did we observe diffusion in the State Lab?

#30 How did we observe diffusion in the State Lab? Diffusion Through a Membrane

#30 How did we observe diffusion in the State Lab? RED ONION IN FRESH WATER

#30 How did we observe diffusion in the State Lab? Red Onion in Fresh Water cytoplasm cell membrane cell wall red onion cells in tap water

#30 How did we observe diffusion in the State Lab? Add Salt Water to Cells bathing the cells in Na. Cl = salt water, by “wicking” it through Na. Cl

#30 How did we observe diffusion in the State Lab? RED ONION IN SALT WATER

#30 How did we observe diffusion in the State Lab? Diffusion Through a Membrane cytoplasm cell membrane red onion cells in salt water cell wall

#30 How did we observe diffusion in the State Lab? Diffusion Through A Membrane bathing the cells in distilled water, by “wicking” it through

#30 How did we observe diffusion in the State Lab? Diffusion Through a Membrane cytoplasm cell membrane cell wall red onion cells in distilled water – returned to normal

#30 How did we observe diffusion in the State Lab? Diffusion Through A Membrane Which cell is in distilled water and which is in salt water?

#30 How did we observe diffusion in the State Lab? Diffusion Through A Membrane Applications – § salt on roads to melt snow § intravenous saline solutions § salty foods make you thirsty § salt on slugs to kill them § salty foods do not spoil as easily § gargling with salt water § digestion of starch to glucose

#30 How did we observe diffusion in the State Lab? • Quick video of what happened to iodine in “cell” tube • A diffusion lab for absent students • Student summary of diffusion state lab • Osmosis demo with raw egg

#30 How did we observe diffusion in the State Lab? Activity – Analysis Questions • Your table will be assigned one question from the analysis section on pages 8 and 9 • Work on the question with your table for 5 minutes and put your answer on your easel. • Be ready to share and explain to your classmates ** If you finish early, check that ALL other sections of the lab are complete

#30 How did we observe diffusion in the State Lab? REGENTS PRACTICE Reflection Answer on looseleaf and attach to lab 1. How did we observe diffusion and osmosis in this lab activity? Did this help with your understanding of these concepts? Explain. 2. Why was lab safety important during this activity? 3. What was your favorite part of this lab? What was most challenging?

#30 How did we observe diffusion in the State Lab?

#30 How did we observe diffusion in the State Lab? Ticket out the Door Think of our experiment yesterday… 1. What molecule diffused OUT of the “cell”? Why was it able to? 2. What molecule could NOT diffuse out of the “cell”? Why not? 3. What molecule diffused INTO the cell? What did it react with in the cell? How could you tell it reacted?