MCQ for Dialysis

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Question 1: In dialysis, the net movement of small size impurities from a solution is by ________. The impurities moves from an area of ______ concentration to _______concentration until equilibrium is established.
  • INCORRECT. Please try again.
  • INCORRECT. Please try again.
  • INCORRECT. Please try again.
  • CORRECT. The net movement of molecules in solution is by diffusion. The molecules move from an area of high concentration to low concentration until equilibrium is established.
Question 2: What is the reason for replacing the dialysis buffer with fresh one after 2 hours of dialysis?
  • INCORRECT. Temperature for the buffer should not be changed. Please try again.
  • CORRECT. Once equilibrium is reached, the final concentration of molecules in sample is dependent on the volume of the buffer involved, and if the equilibrated buffer is replaced with fresh buffer, diffusion will further reduce the concentration of the small molecules in the sample.
  • INCORRECT. Please try again.
  • INCORRECT. Please try again.
Question 3: Dialysis times can be shortened by :
i. Leaving some space for the solution to flow into the dialysis tubing.
ii. Using more porous dialysis tubing.
iii. Turning the stirrer to allow the dialysis tubing to rotate slowly in buffer.

  • INCORRECT. One of them is wrong. Please try again.
  • CORRECT. Rapid equilibrium is attained by these two methods.
  • INCORRECT. One of them is wrong. Please try again.
  • INCORRECT. One of them is wrong. Please try again.
Question 4: There are several different dialysis devices available for laboratory experiment, apart from dialysis tubing, which of the following is/are the dialysis device(s) that can be used?
i. Dialysis button
ii. Dialysis slide (cassette)
iii. Hockey stick
  • INCORRECT. Please try again.
  • INCORRECT. Please try again.
  • INCORRECT. Please try again.
  • CORRECT. All of them are dialysis devices. Dialysis buttons are available in various volumes and they are easy to handle. The dialysis surface is sufficient, but sampling during the experiment is difficult. Dialysis slides (cassettes) have a large surface area, provide for easy sampling, but are expensive for extended screens. “Hockey sticks” are bent glass tubes which are sealed by a dialysis membrane on one end. The sampling is easy, but the dialysis surface is small.
Question 5: What factor of the semipermeable membrane should be considered for retaining a protein in the sample and allows small impurities such as sodium chloride, to pass through?
  • INCORRECT. Increasing the surface area can shorten the dialysis time, but it is not the determining factor for the mentioned purpose. Please try again.
  • INCORRECT. More porous tubing can shorten the dialysis time, but it is not determining factor for the mentioned purpose. Please try again.
  • CORRECT. The molecular weight cutoff (MWCO) of the semipermeable membrane should be considered such that it will retain protein in the sample and allows small impurities, such as sodium chloride, to pass through.
  • INCORRECT. Please try again.