Question

In eukaryotic cells (cells with a nucleus), ribosomes have two major subunits, a 60s and a 40s. if we assume both are spheres and have the same average density, what are their relative sizes?

Answer 1

Molecular weight of 60s sub unit = 2.7 x 10^6 units

Molecular weight of 40s sub unit = 1.3 x 10^6 units

Densities are same and both are spherical

Relative size = Molecular weight of 60s / molecular weight of 40s = 2.7 x 10^6 / 1.3 x 10^6 = 27/13 = 2.0769