DNA

** DNA Structure! **

FUN FACT! ** If you unwrap all your DNA, you could reach the moon and back 6000 times!

Alright kiddies, open up your learn-holes, and prepare to be knowed. **DNA** stands for **Deoxyribonucleic Acid**. It stores and transmits the genetic information needed to create the proteins that program your body. It's shape was discovered by **James Watson** and **Francis Crick**.

DNA is in the shape of a **double helix** and codes for just about everything in your body. The helix is made up of **nucleotides**. The nucleotides consists of a **phosphate, a sugar, and a base**. The sugar is deoxyribose, the phosphate is a phosphorous and oxygen. and the base is one of the 4 bases. The bases are what code for all the proteins in your body. There are 4 bases. **A (Adenine), G (Guanine), T (Thymine), C (Cytosine)**. This creates the two **polynucleic strands** that are wrapped around each other. The bases are held together by **hydrogen bonds**

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 * DNA Replication! **

[|**DNA Replication Animation**] **DNA replication** starts with the breaking apart of the DNA strands. The **Helicase** breaks apart the hydrogen bonds to do this. The **binding protein** then are used to hold the strand apart. Next an **RNA primer** is laid down by the **Primase**. This signals the starting point of replication on the leading strand. The **Polymerase** then builds the rest of the strand straight from there. Finally the **Polymerase** replaces the original RNA primer with DNA.

Because the helix uncoils in opposite directions, the **lagging strand** takes a much more difficult process to replicate. The **Primase** must create multiple **RNA primers**, then the **Polymerase** is able to create a small strand of DNA between the primers. Then the **Polymerase** replaces all primers with DNA. Finally, since it was done in fragments, the **Ligase** goes over the new strand and makes sure all strands are bound together. These pieces on the lagging strand are often called **Okazaki fragments**.

DNA page by Steve