Gel Electrophoresis Questions and Answers

Multiple Choice Questions and Answers on Gel Electrophoresis

Question 1 : In a gel filtration column

  1. smaller proteins enter the beads more readily
  2. large proteins elute first
  3. both (1) and (2)
  4. large proteins enter the beads more readily

Answer : 3

Question 2 : In a native PAGE, proteins are separated on the basis of

  1. net negative charge
  2. net charge and size
  3. net positive charges size
  4. net positive charge

Answer : 2

Question 3 : The subunit molecular weight as well as the number of subunits in the quaternary structure can be determined by

  1. SDS-PAGE electrophoresis
  2. gel filtration chromatography
  3. combining information from (1)and (2)
  4. isoelectric focusing

Answer : 3

Question 4 : Proteins are separated in an SDS-PAGE experiment on the basis of their

  1. positively charged side chains
  2. molecular weight
  3. negatively charged side chains
  4. different isoelectric points

Answer : 2

Question 5 : In an SDS-PAGE

  1. proteins are denatured by the SDS
  2. proteins have the same charge-to-mass ratio
  3. smaller proteins migrate more rapidly through the gel
  4. all of the above

Answer : 4

Question 6 : Proteins can be visualized directly in gels by

  1. staining them with the dye
  2. using electron microscope only
  3. measuring their molecular weight
  4. none of these

Answer : 1

Question 7 : In SDS-PAGE, the protein sample is first

  1. treated with a reducing agent and then with anionic detergent followed by fractionation by electrophoresis
  2. fractionated by electrophoresis then treated with an oxidizing agent followed by anionic detergent.
  3. treated with a oxidizing agent and then with anionic detergent followed by fractionation by electrophoresis
  4. none of the above

Answer : 1

Question 8 : Electrophoresis of histones and myoglobin under non-denaturing conditions (pH = 7.0) results in

  1. both proteins migrate to the anode
  2. histones migrate to the anode and myoglobin migrates to the cathode
  3. histones migrate to the cathode and myoglobin migrates to the anode
  4. both proteins migrate to the cathode

Answer : 3

Question 9 : In isoelectric focusing, proteins are separated on the basis of their

  1. relative content of positively charged residue only
  2. relative content of negatively charged residue only
  3. size
  4. relative content of positively and negatively charged residue

Answer : 4