Actin filaments have polarity.This means that the two ends can be identified due to structural differences.The plus end is the end to which subunits are added more rapidly,or the end of polymerization.Which of the following would enable you to identify the plus end of actin filaments?
A)Add radiolabeled actin subunits to a mixture of actin filaments in which conditions are favorable for polymerization.
B)Add radiolabeled actin subunits to a mixture of actin filaments in which conditions favor depolymerization.
C)Determine the ionic charge of the ends of the actin filaments.

Question

Quizplus · Accepted Answer

By adding radiolabeled actin subunits to a mixture of actin filaments in which conditions are favorable for polymerization, we can observe which end of the filament is adding subunits at a faster rate, indicating the plus end. In option B, conditions favoring depolymerization would make it difficult to observe the direction of subunit addition. Option C is not relevant to identifying the polarity of actin filaments.

Actin Filaments Have Polarity