Final answer:
Smaller, highly charged molecules and compact structures like supercoiled DNA exhibit the best electrophoretic mobility because they move faster and further in a gel during electrophoresis.
Step-by-step explanation:
The types of molecules that have the best electrophoretic mobility are those that are smaller in size, more compact in structure, and have a higher net charge. DNA fragments move through a gel matrix during gel electrophoresis according to their size and charge, with the smallest fragments moving the fastest. The electrophoretic mobility is affected by the charge of the molecule (q), the strength of the electric field (E), and friction (f), as represented in the equation v=qE/f. Therefore, smaller, highly charged molecules and those with more compact shapes, such as supercoiled DNA, will travel further and faster in a gel than larger, less charged or more elongated molecules.
Molecules with smaller size and higher charge have the best electrophoretic mobility. In gel electrophoresis, molecules are separated based on their size and charge. Smaller molecules with higher charge move faster through the gel matrix and are separated more effectively. For example, in DNA electrophoresis, smaller DNA molecules with higher charge travel farther in the gel compared to larger DNA molecules with lower charge.