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Osmosis And Diffusion Lab Report

388 Words2 Pages

Isra Romani
Lab Report 2: Diffusion and osmosis through non-living membranes

Introduction

Cells contain membranes that are selectively permeable which allow certain things to pass into

and leave out of the cell. The process in which molecules of a substance move from an area of

high concentration to areas of low concentration is called diffusion. Whereas Osmosis is the

process in which water crosses membranes from regions of high water concentration to areas

with low water concentration. While molecules in diffusion move down a concentration

gradient, molecules during osmosis both move down a concentration. During the osmosis both

move down a concentration as well as a cross it. Diffusion and osmosis are type of passive

transport …show more content…

PURPOSE

To provide information on the movement of water and solutes through selectively

permable membranes called dialysis sacs.

Materials

4 dialysis sacs ( have pores on a particular size)

Small funnel

25-ml graduated cylinder

Wax marking pencil

Fine twine or dialysis tubing clamps

4-250ml beakers

Laboratory balance

Glucose solution

Nacl solution

Congo red dye in 40%sucrose solution

Paper towel

Procedure

1. Number the beakers 1 to 4 with the wax marking pencil, and half fill all of them with the

distilled water except beaker 2, to which you should add 125ml of 40%glucose solution.

2. Prepare the dialysis sacs one at a time by using the funnel, half fill each with 20ml of the

specified liquid.

3. Press out the air, fold over the open end of sac, and tie it securely with fine twine or

clamp it before proceeding to the next sac. Rinse it under the tap, and quickly and

carefully blot the sac dry by rolling it on a paper towel.

4. Weigh with a laboratory balance. Record the weight and drop the sac into the

corresponding beaker. Make sure the sac is covered by beaker solution.

Contents of sacs

Sac 1: 40% glucose

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