Osmosis

Instructions:

Follow the directions and complete the activity.

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Introduction

Osmosis is defined as the diffusion of water across a membrane in response to osmotic pressure caused by an imbalance of molecules on either side of the membrane. As you know the red blood cells, like all cells are surrounded by a semipermeable plasma membrane. In this experiment you will observe the fate of red blood cells in different solutions.

When red blood cells are placed in an isotonic solution, they are in equilibrium: they neither gain nor lose water. When they are placed in a hypertonic solution, they will lose water and shrivel up. This process is called crenation. When they are placed in a hypotonic solution, they gain so much water that they eventually burst. This process is called hemolysis. For this experiment, assume that the salt concentration within the cells is 0.9% NaCl.

Credit: https://openstax.org/resources/beb8f5eafb7f08dc3a619385dc9e66574dcfbbdf

Step 1:
Experimental procedure
The following solutions were used for the experiment.
Solution A: 0.9% NaCl
Solution B: 10% NaCl Tube
Solution C: Distilled water
⦁ A drop of blood was added to each of the above solutions and stirred gently.

⦁ A drop of the solution was then placed on a slide.

⦁ After gently placing a coverslip on the slide, the slide was placed under a microscope and results noted.

Step 2:
Please watch the video below to see the results (Copy and paste it in another window for convenience)

(Be patient with the background music)
Complete the table based on the video.
Solution Fate of the Red blood cell Explanation
Isotonic
(0.9% sodium Chloride solution)
Hypotonic
(less than 0.9% sodium chloride solution)
Hypertonic
(greater than 0.9% sodium chloride solution)