restriction enzymes

[determinedfuture]

So I know that restriction enzymes cut DNA at specific palindrome sequences, but what is the whole purpose of restriction enzymes? How do people use them? I'm asking this because I'm trying to get the bigger picture in regards to their function.

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[ScrubsMD]

How about you Google it. It's a big topic. They're necessary to do most things in molecular biology.

 

[jamcat]

This would be a good one to google or to check your Intro Bio textbook, or a "methods" section of an MCAT bio book for, but in general:

1. Cells use them "naturally" for defense. They can cut up foreign DNA that's not supposed to be in the cell (like viral or bacterial DNA) if they have the right sequence.

2. We use them in the lab for alllllll sorts of things, primarily moving DNA around and checking to see if what we have is what we think we have. Google and your textbook are really your friends here because it's possible to write entire books on the subject (and people have!). Here's the wikipedia page to get you started: http://en.wikipedia.org/wiki/Restriction_enzyme#Applications

 

[KungFuPanda123]

Basically what Jamcat posted.

For his #1, it's basically all you need to know. Foreign DNA = bad, so bacteria try to destroy it by using restriction enzymes which cut up the DNA in specific regions where a set sequence is (a given restriction enzyme cuts up a given sequence).

For #2 - look up "recombinant DNA" in Google. Restriction enzymes let you take a plasmid (circular DNA) and cut it up in 1 particular region (making it 1 straight piece of DNA). You can then take a certain gene and cut it (using the same restriction enzyme) and combine it with the cut up plasmid. You combine them by using DNA ligase.

Once combined, this plasmid + inputted DNA is called "recombinant DNA." It can be given to certain cells to make them express the gene that you stuck in.

 

[JPSmyth]

So I know that restriction enzymes cut DNA at specific palindrome sequences, but what is the whole purpose of restriction enzymes? How do people use them? I'm asking this because I'm trying to get the bigger picture in regards to their function.

in Molecular Bio they were really emphasized for recombinant DNA as Kung Fu Panda said. Also, they can be used for restriction fragment length polymorphism analysis in Genetics

for instance, if somebody's DNA has a mutation that gives them the sequence recognized by a specific RE, then you can run it in a gel and see if there are two fragments rather than one, they must have the mutation at that locus. (in a highly simplified way)