Rank the following proteins from smallest to largest expected sedimentation coefficient:
1. Protein A has 250 amino acids, is a monomer, and is nearly spherical in shape.
2. Protein B is a dimer with 500 amino acids in each subunit, and is nearly spherical in shape.
3. Protein C has 700 amino acids, is a monomer, and is nearly spherical in shape.
4. Protein D has 250 amino acids, is a monomer, and is a significantly elongated.

Protein D, A, C, B

Explanation:

The sedimentation coefficient of a protein is gives a characteristics of the protein's sedimentation during centrifugation. It is not only dependent on the size of the particle but also on the shape of particles and other factors including the properties of the fluid they are suspended in.

Heavier particles do sediment faster and have higher sedimentation coefficients value which is always in sverdberg units.

Thus, Protein D with 250 amino acids, a monomer, and is a significantly elongated will have a lower sedimentation coefficient than Protein A with 250 amino acids, a monomer, and is nearly spherical in shape due to the shape of these two proteins

Since Protein B is a dimer (made up of two monomers), it is the largest with the highest sedimentation coefficient.

Protein A has a smaller sedimentation coefficient than protein C due to the different in the number of amino acids.