A Basic Understanding of Diffusion and Osmosis

A Basic Understanding of Diffusion and Osmosis

The purpose of this lab was to have a basic understanding about

concepts diffusion and osmosis. In this lab we had dialysis tube as a

cell membrane of cell, which lets small particles pass through it and

we had test tube as tightly joined surface, which doesn’t let any

particles pass through it. As a result we saw that small particles

like glucose and iodine diffused through dialysis tube, but large

particle like starch couldn’t diffuse dialysis tube. From this lab it

can be concluded that small particles like glucose and iodine can pass

through phospholipid’s double layer of cell membrane to provide

nutrition to cell, but larger particles like starch needs to go

through the entrance of cell.

Introduction:

Diffusion is the movement of molecules from an area of higher

concentration to an area of lower concentration. Osmosis is the

diffusion of water molecules across a selectively permeable membrane.

The purpose of this lab is to identify the particles that can diffuse

through dialysis tube. I hypothesized that starch and glucose can

diffuse through the dialysis tube. My null hypothesis was that none of

these particles would be able to diffuse through the test tube in

beaker.

Materials:

Refer to lab manual (page 53) in Nelson Biology 11.

The following revisions were made.

-We used Fehling’s solution instead of Tes-tape for glucose test.

Experimental Procedure:

Refer to lab manual (page 54-55) in Nelson Biology 11.

Results/Observations:

Table 1: Color of the solution or Suspension

Initial Observations

After 20 minutes

Dilute Lugol’s solut...

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...Error.

Since this experiment was done by a human and not by a robot it was

usual that there should be a source of error. While we were doing this

lab we faced some problems that affected our experiment. We had some

minor problems that didn’t do much bad, but our major problem wasted

our time, which we lacked. In this lab we had to tie two ends of

dialysis tube tightly, but by mistake there was a lose point in our

dialysis tube of starch. This leaking of starch was ruining beaker’s

solution and as well as our solution, which made lab worth no use. So

to have a good lab we had to everything again which wasted a lot of

time, but still we covered it all and got it all right. The other

problems like usage of contaminated solution and amount didn’t matter

a lot, so it was fine. But, as a result our lab was a great success.