A group of eight students has taken a sample of their own cheek cells, purified the DNA, and used a restriction enzyme known to
cut at zero, one, or two sites in a particular gene of interest. They then run the fragments through gel electrophoresis and use a fluorescent probe. Why might they be conducting such an experiment.
Gel electrophoresis is a technique used to separate DNA fragments by size and charge. Electrophoresis consists in applying a current through a gel that contains the molecules of interest. Based on their size and load, the molecules will travel through the gel in different directions or at different speeds, thereby separating each other. All DNA molecules have the same amount of charge per mass. Because of this, gel electrophoresis separates DNA fragments only by their size.
Electrophoresis allows us to see how many different DNA fragments are present in a sample and how large they are with respect to each other. We can also determine the absolute size of a DNA fragment by examining it next to a standard "scale" of fragments of known size.
During termination, the ribosome unbinds from the mRNA, and the amino acid chain goes on to be processed and folded to make the final, functional protein.
