Active transport question
Solution
1. Since the Visking bag acts as a semipermeable membrane therefore it allows movement of only certain substances (for example water molecules and iodine solution) inside.
As a result the presence of the starch solution contained in the bag makes the iodine (which moved inside along with water molecules) turn blue black and hence the blue black colour appears inside the bag.
On the other hand since water on the outside does not contain any starch therefore the iodine solution does not turn blue black and remains brown. This indicates that substances moved inside the Visking bag and starch molecules were not able to move outside it.
2. Factors that influence movement of molecules through membranes are as follows -
1. Concentration
2. Pressure
3. Membrane type
1. Since the Visking bag acts as a semipermeable membrane therefore it allows movement of only certain substances (for example water molecules and iodine solution) inside.
As a result the presence of the starch solution contained in the bag makes the iodine (which moved inside along with water molecules) turn blue black and hence the blue black colour appears inside the bag.
On the other hand since water on the outside does not contain any starch therefore the iodine solution does not turn blue black and remains brown. This indicates that substances moved inside the Visking bag and starch molecules were not able to move outside it.
2. Factors that influence movement of molecules through membranes are as follows -
1. Concentration
2. Pressure
3. Membrane type