Question

DNA molecules of different sizes are often separated with the use of a technique called electrophoresis. With this technique, DNA molecules are placed in a gel, an electrical current is applied to this gel, and the DNA molecules migrate toward the positive pole of the current. What aspect of its structure causes a DNA molecule to migrate toward the positive pole?

Answer 1

Step-by-step explanation:

The DNA is a chain of nucleotides. Each of them has a nitrogenous base (cytosine, thymine, adenine or guanine), a sugar called deoxyribose and a phosphate group.

The phosphate groups are negatively charged, and because of them the DNA molecule will be attracted to the positive pole during electrophoresis.

I'm attaching two figures: a nucleotide and a a DNA molecule (extracted from Organic Electronics, pp.73-112).