Question

Which of the following is a weakly basic anion exchange resin?

	A.	DEAE cellulose
	B.	Dowex-50
	C.	CM cellulose
	D.	Sephadex
	E.	Dowex-1

Which of the following amino acid sequences is most likely to be part of a Type II reverse turn?

	A.	SVPWFF
	B.	VYRHSL
	C.	RALGFD
	D.	GPPRPP
	E.	AGPYSA

Parallel beta-sheets are less stable than anti-parallel because?

	A.	the H-bonds are not linear
	B.	steric interactions between R groups lowers stability
	C.	the H-bonds are linear
	D.	the parallel has disufide bonds between chains
	E.	parallel sheets have higher dipole moments because all carbonyls are aligned

Based on your knowledge of the alpha-helix, which interaction is likely to destabilize the helix?

	A.	the presence of several Ala in the sequence
	B.	the presence of a Glu at the N-terminal
	C.	the presence of a Ser at the C-terminal
	D.	the presence of an Arg at the C-terminal
	E.	the presence of two Lys at the N-terminal

Answer 1

soluhon a weakly basic anion exchange resin is. a DEAE cellulose is used as weak basic anion exchange resin. b. Dowex - so is used as shong cahºon exchange resin cm cellulose Sephader is is used as weak cahon exchange resin used for gel fi'hation: basic anion Exchange Dowex - 1 is used as strongly resin A turn is defined by u amino acids i it, i+2, it3. There is steric hindrance of residus it 2 with the carbonyl oxygen or preceding residue in type wrever turn. ei hi i Hence ita posi non can be et posi non can be occupied by glycine only in type 2 reverse turn to minimize the " PAIGED ie ophion "c. is most likely to be part or type 2 reverse turn because it hay glycine at itzo (start counhing from left). Any other amino avoid.co doesn't thave glycine at ita position fophim " . her amino avoid sequence . position ſophiem "c is coneel