Question

In gel electrophoresis why does the DNA move toward the bottom of the wall of gel? A. DNA is negatively charged. B. DNA is positively charged. C. DNA is extremely heavy. D. DNA is less dense than air.

Answer 1

A. The DNA is negatively charged.

Answer 2

The correct answer is option A. "DNA is negatively charged".

Step-by-step explanation:

The molecules of Deoxyribonucleic acid (DNA) have a negative charge because of the negative charge of phosphate component located in its ribose-phosphate backbone. This property of DNA is used during gel electrophoresis to separate the molecules according to its size. One molecule of DNA has a one negative charge, and moves towards the bottom of the wall of the gel because is where the anode is located. The larger the size of the DNA the faster it will move to the anode.