Question

Upon centrifugation, particles sediment at different rates due to their physical properties. Tropomyosin is a rod-shaped protein with a mass of 70 kDa and a sedimentation coefficient of 2.6S. Hemoglobin is a spherical protein with a slightly smaller mass of 65 kDa, but a much higher sedimentation coefficient of 4.31S. Which property of tropomyosin accounts for its slow sedimentation?

Answer 1

Answer:

Elongated shape

Explanation:

Centrifugation separates molecules on the basis of angular motion.

Due to spherical shape, the value of 'f' is lesser for a spherical protien than the rod shaped one.

Hence the sedimentation coefficient for an elongated protien is 2.6S while htat of a spherical protien is 4.31S.

Hence its elongated shape results in slow centrifugation.

Some of the important principles of centrifugation are as follows :

• The greater the mass, the more is the sedimentation rate i-e the one with greater mass will move down more rapidly as compared to the one with les mass.
• Shape of particles also effect it, the rounder the particle, the lower frictional coeeficient.
• Density of particles
• Density of fluid