The secondary structure shown below is an example of a(n):
A) parallel $\beta$ sheet.
B) antiparallel $\beta$ sheet.
C) right-handed $\alpha$ helix.
D) left-handed $\alpha$ helix.
E) $\beta$ turn.

Question

The secondary structure shown below is an example of a(n): 
A) parallel $\beta$ sheet. 
B) antiparallel $\beta$ sheet. 
C) right-handed $\alpha$ helix. 
D) left-handed $\alpha$ helix. 
E) $\beta$ turn.

Quizplus · Accepted Answer

The secondary structure shown is a beta sheet, as indicated by the arrows pointing in opposite directions. The fact that the arrows are not parallel to each other suggests that this is an antiparallel beta sheet, rather than a parallel one. The F and S refer to beta strands and turns, respectively. So the correct answer is B, antiparallel F1F1F1S1βF1F1F10 sheet.

The Secondary Structure Shown Below Is an Example of A(n) β\betaβ

The Secondary Structure Shown Below Is an Example of A(n) $\beta$