For the two following graphs, the same purified protein has been subjected to velocity sedimentation and gel filtration, as indicated. Two absorption peaks are visible in each graph, corresponding to the monomeric and dimeric forms of the protein. Which peaks correspond to the protein dimer?

Three subunits of a protein complex have been resolved in a two-dimensional polyacrylamide gel, as shown in the schematic drawing below. Indicate whether each of the following better describes the a, b, or c subunit. Your answer would be a three-letter string composed of letters a, b, and c only, e.g. cca.

( ) It has the smallest apparent molecular weight.
( ) It has the highest negative charge.
( ) It has the lowest isoelectric point.

Indicate whether each of the following descriptions applies to transformed cell lines (T), nontransformed cell lines (N), or both (B). Your answer would be a four-letter string composed of letters T, N, and B only, e.g. BBNN.
( ) They can be thawed and recultured after long-term storage in liquid nitrogen.
( ) They often grow only when attached to a surface, such as that of a culture dish.
( ) They proliferate to very high densities.
( ) They usually cause tumors when injected into immunocompromised animals.