Osmosis Lab

Question: What does water do in a osmosis operation?

Procedure: Have two beakers, salt, water, two dialysis tubes, and a weight . Fill one of the beakers with salt and water and one beaker with just water. Grab a dialysis tube and pour salt into it the dialysis tube then grab another dialysis tube and pour water into it. weigh the two dialysis tubes before you put it into the the beaker then put the one with just salt into the beaker that has just water and then the dialysis tube with just water put it into the beaker with salt and water. Then after a day take the two dialysis tubes out of the beakers and weigh them again. The dialysis tube with salt should weigh more than the dialysis tube with just water.

Claims: The dialysis tube with salt weighs more than the one with water because of osmosis.

Evidence: 

Research: Osmosis is when molecules move through a semi permeable membrane into a region of higher solute concentration, in the direction that tends to equalize the solute concentrations on the two sides.

Reflection: I learned how osmosis can affect a cell membrane.

Cell membrane

In this lab I chose people into my group and we had to find a picture of a cell-membrane in google images and draw it the reason we did this was so we can understand what a cell-membrane is and learn what can pass through a cell-membrane and what can't go through a cell membrane.

Diffusion and Osmosis Lab

Question: Why couldn't the starch get out?

Procedure: have a beaker, dialysis tube, test-tape (For recording Glucose levels), glucose, and starch, and Iodine. Fill the beaker with water almost at the top of the beaker and add a bit of iodine. Now test the beaker with the test tape and record the color of the mixture. Then grab a dialysis tube and open one side and then tie the bottom next fill it with 15% glucose and 1%starch then test it with the test tape and now tie the top of the bag and put it in the beaker. Next, wait 30minutes or wait for a distinct color change and record the beaker and dialysis tube again with the test tape.

Claims: the reason the starch didn't get out of the dialysis tube because the size of the molecules were too big for it to pass through the tiny pores of the dialysis tube.

Evidence: The before and after pictures 

Research: Diffusion is the movement of particles from an area of high concentration to an area of lower concentration. Osmosis is the diffusion of water from a hypotonic solution across and selectively permeable membrane.  

Reflection: Now I know that not everything can pass through a membrane.


Hypotonic definition: having a lower osmotic pressure than a particular fluid, typically a body fluid or intracellular fluid.

Permeable definition: (of a material or membrane) allowing liquids or gases to pass through it.