They cut it up into smaller nonfunctional fragments. Now, biochemists can actually extract and clone these restriction enzymes from these bacterial cells and prokaryotic cells, and we can use them for a variety of different purposes as we'll discuss in the next several electros. So there are four purposes I've listed on the board. So we can use them to analyze and study some DNA molecules that we're interested in. We can also actually use them to determine the actual sequence of nucleotides of very, very long DNA molecules. So if we have a long DNA molecule, we can use these restriction enzymes to cut the molecule to smaller fragments and then we can determine what the sequence is of the smaller fragments.