Question

Persistence length for a cytoskeletal filament is the minimum filament length at which random thermal fluctuations are likely to cause it to bend. Which of the following comparisons are true, considering the persistence lengths of (a) an actin filament, (b) a bundle of cross-linked actin filaments, and (c) a microtubule

Answer 1

The provided question is incomplete as the group of choices were not given, however, the choices as follows:

A. (a > b) and (a > c)

B. (a > b) and (a < c)

C. (a < b) and (a > c)

D. (a < b) and (a < c)

E. (a > b) and (b > c)

Answer:

The correct answer is - D. (a < b) and (a < c)

Explanation:

The persistent length of actin filaments,  a bundle of cross-linked actin filaments and microtubules can be compared on their typical persistent length.

The persistent length of actin filaments is 15 µm. And due to the crosslink with one another to make a bundle their length reduced  As the actin filaments cross-link each other their persistent length will be reduced. however, it is still longer than single actin filament around 20 nm.

The persistent length of microtubules is 6mm.

So b > a, a < b and a < c.

So fourth option a < c and b > a is the correct answer.