Question

Scientists can determine the size of DNA fragments through a process known as gel electrophoresis. In this process, DNA is loaded into a gel submerged in a liquid solution through which an electric current is run. Large DNA molecules move slower and can be observed at the top of the gel, whereas smaller DNA fragments move faster and are seen at the bottom of the gel. Based on what you know about the properties of DNA, how is the electric current arranged in this process?

Answer 1

Answer:

DNA sample is loaded at the negative end of the gel and is made to move towards the positive terminal present at the opposite end.

Explanation:

DNA is a polymer of deoxyribonucleotides. Each of deoxyribonucleotides has a nitrogenous base, phosphate, and pentose sugar. The presence of the phosphate groups imparts a negative charge to the sugar phosphate backbone of DNA. Since DNA is negatively charged, it should be loaded at the negative terminal of the gel electrophoresis chamber and should be made to move towards the positive terminal present at the other end of the apparatus.