pag visking tubing

Question 1

what is visking tubing

Answer 1

• non-living partially permeable membrane made from cellulose
• pores in this membrane are small enough to prevent the passage of large molecules (such as starch and sucrose) but allow smaller molecules (such as glucose) to pass through by diffusion

Question 2

outline method

Answer 2

• fill a section of visking tubing with a mixture of starch and glucose solutions
• suspend the tubing in a boiling tube of water for a set period of time
• test the water outside of the visking tubing at regular intervals for the presence of starch and glucose to monitor whether the diffusion of either substance out of the tubing has occurred

Question 3

what are the expected results

Answer 3

• glucose diffuses out of tubing

- starch does not diffuse out of tubing