How Much of DNA Is Untwisted During Replication?
DNA untwists during replication in order to produce an identical cell, and it untwists little by little until two separate cells are completely produced. Understand the process of DNA replication with information from a biology teacher in this free video on science.
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Have you ever wondered exactly what it is that makes your hair or your fingernails grow? Or exactly how it is that a cut heals? I'm Janice Crenetti. I've been teaching biology for over 20 years in high school and I'm here to share with you today how much of DNA is untwisted during replication. Well first of all, let's talk about what DNA replication is. DNA replication is the body's process of producing more DNA. On the screen here I have a DNA molecule and you'll notice that the DNA molecule is twisted up. Scientists refer to that as a double helix. Well in order for DNA to replicate, this double helix has to unzip. First it untwists and then it's going to actually begin to unzip just like if you were to unzip a zipper on your jacket. And a little bit at a time of this DNA molecule will open up. There's an enzyme called DNA polymerases that's going to actually come in and carry the bases and build a whole new DNA strand. Well what will happen is as this DNA strand completes itself, I'll have a strand here and then I'll have a strand here, and then a little bit more of my DNA strand will unzip. So it unzips just a little bit at a time until the entire strand has been turned into two exact duplicate copies. So your hair, each cell, is genetically identical to the cell from which it came. The same thing is true of your fingernails. The same thing is true of your skin. That's why your brown hair doesn't all the sudden start growing blond. It's got the same genetic information as the stuff that came out of your head. DNA replication is a very important process for growth, for development and for healing. I'm Janice Crenetti and this is how much of DNA is untwisted during replication.