STEM PRESENTATION

MOVEMENT OF MOLECULES

PRESENTATION

CREATED BY: Giovanni Sansone, Giovanni Pisacane. Pasquale Melucci, Alex Lupu

OBJECTIVE

The objective of this experiment is to simulate the functions of a semi-permeable cell membrane and to explore the differences in the movement of molecules into and out of a semi-permeable membrane.

INTRODUCTION

A previous experiment focused on the cell wall structure in plant cells, noting pectin's role and breakdown by pectinase. Cell walls provide support and allow free substance movement. Unlike the cell wall, the cell membrane has a flexible structure with smaller gaps, permitting only small water molecules to pass freely. Larger molecules require special channels. To explore the semi-permeable properties of the cell membrane, an experiment will be designed.

MATERIALS

FEHLING'S SOLUTION

TWO PIPETTES

TWO BECKER

POTATO STARCH

DISTILLED WATER

BAG CLIPS

MESUARING CYLINDER

A SPOON

SACCHAROSE

TWO SEMI PERMEABLE BAGS

LODINE SOLUTION

ELECTRONIC BALANCE

STEP 1

insert 50 ml of water into each beaker

STEP 2

In the first beaker we will insert the Fehling's solution, in the second the lodine solution

STEP 3

In two paper trays, we are going to insert the potato starch and the saccharose and then we are going to weigh them on the electronic balance (5g for each)

STEP 4

We use semi-permeable bags, in the first we will put the succharose, in the second the potato starch, in both we will then insert some water and close them with the bag clips

STEP 5

Gently massage the two semi-permeable bags

STEP 6

In the end we will immerse the two semi-permeable bags in the two beakers and wait for a few hours

CONCLUSION

Unfortunately the experiment did not end well, in fact in the second beaker (where the lodine solution was) we find the saccharose which does not penetrate the permeable bags and we get a transparent color

THANKS FOR THE ATTENTION