## What is the persistence length of a polymer?

The persistence length equals the average projection of the end-to-end vector on the tangent to the chain contour at a chain end in the limit of infinite chain length. , the Young’s modulus E and knowing the section of the polymer chain.

## What is meant by the contour length of a polymer?

Contour length is a term used in molecular physics. The contour length of a polymer chain (a big molecule consisting of many similar smaller molecules) is its length at maximum physically possible extension. Contour length is equal to the product of the number of segments of polymer molecule(n) and its length(l).

How is polymer persistence length measured?

Calculation of Persistence Length. 〈 r i ⋅ r i + s 〉 = l 2 〈 cos θ ( s ) 〉 = l 2 exp ( − s l / l p ) . Here, s is the chemical distance between two bonds, and l is the bond length.

What is DNA persistence length?

DNA is among the stiffest of known polymers with a persistence length of ∼50 nm (150 bp) in 0.1 M aqueous NaCl.

### What is persistence length of microtubules?

Microtubules are important for defining morphology and providing mechanical stiffness to cells. The mechanical properties of microtubules have therefore been studied intensively for over a decade (1–7). The consensus was that microtubules can be characterized by a persistence length of 4–8 mm (1,6).

### What is end to end distance in polymer?

If each monomer unit in a polymer is represented by a point in space, the translation vectors connect between these points. The end-to-end vector. is the sum of these translation vectors: The norm of the end-to-end vector is called the end-to-end distance.

What is the contour length of a protein?

For this reason, the cited values for the contour length per amino acid, l, vary from protein to protein, spanning from 3.4 Å (2) to 3.6 Å (3,15,16), 3.8 Å (4–6), and further up to 4.0 Å (7).

What is end-to-end distance in polymer?

#### Why are microtubules stiffer than actin?

The greater flexural rigidity of a microtubule compared to an actin filament mainly derives from the former’s larger cross-section. If tubulin were homogeneous and isotropic, then the microtubule’s Young’s modulus would be approximately 1.2 GPa, similar to Plexiglas and rigid plastics.

#### What is a cytoskeletal polymer?

The cytoskeleton is a polymer network composed of three linear biopolymers: F-actin, microtubules, and intermediate filaments. The polymerization of these filaments from their subunits is controlled by a host of regulatory proteins.

What is characteristic ratio polymer?

The characteristic ratio, Cn, is the ratio of observed end-to-end distance, and the end-to-end. distance of a freely jointed chain composed of n bonds of step length lchem, Cn = r2. 0.