Question 19 (1 point)

The same Protein X was purified from tissue source A and tissue source B, yielding the following results:

Protein X, sample A: specific activity = 1000 U/mg; fold-purification = 100

Protein X, sample B: specific activity = 100 U/mg; fold-purification = 1000

Which of the following statements are correct? Each correctly assigned choice will earn you 0.2 marks.

Question 19 options:

	Protein X, sample A has a higher level of purity than Protein X, sample B.
	Protein X, sample B has a higher level of purity than Protein X, sample A.
	Tissue source A has a higher specific activity for Protein X than tissue source B.
	Tissue source B has a higher specific activity for Protein X than tissue source A.

Question 20 (1 point)

Protein A: 50 kDa, pI = 5

Protein B: 80 kDa, pI = 9

Protein C: 50 kDa, pI = 9

When comparing SDS-PAGE, native PAGE and isoelectric focusing, which of the following are true statements? More than one choice may be correct. Assigning each choice correctly as true or false will earn you 0.2 marks.

Question 20 options:

	Two-dimensional gel electrophoresis would be effective at separating a mixture of proteins A, B and C into 3 separate spots.
	Protein A will migrate towards the positively charged electrode (anode) if the buffer is at pH 7 in native PAGE.
	Isoelectric focusing would be effective at separating protein B from protein C.
	SDS-PAGE would be effective at separating protein A from protein C.
	Protein A will migrate towards the positively charged electrode (anode) if the buffer is at pH 7 in SDS-PAGE.