Just Thought You Should Know

The reason why people in the army solute is because knights lifted up their helmet visors so that their friends could identify them. This is actually just one theory. There are many different theories to the origin of the salute. This one is my favorite. Just thought you should know.

DNA Follow-up

Here's a little more detail of what makes up DNA. DNA is made up of repeating subunits called nucleotides. These nucleotides have three parts to them, a sugar molecule called dioxiribose, a phosphate group, and a nitrogen-containing base. The four nitrogen-containing bases are adenine, cytosine, guanine, and thymine (ACGT). Adenine pairs with thymine and guanine pairs with cytosine. They are bonded together with hydrogen bonds. If you think of DNA as a ladder, the base pairs would be the rungs. I could go further. Maybe I will in another post.

Now, I'll talk about DNA replication. First, DNA is separated into two strands. They are split apart by enzymes called helicases. The reason that the base pairs are bonded together by hydrogen bonds is for this very process. Hydrogen bonds are easy to break. Now, enzymes called DNA polymerases move down along the two strands of DNA. As they move along the chains, new chains are assembled using the nucleotides in the surrounding area. The bases must pair with the right bases. Take this imaginary strand: ACCGTATCG. The new strand that would be formed along that would be TGGCATAGC. Replication results in two new copies of the original DNA. Each copy has one old strand and one new strand.

So there you have it. A little insight into the world of DNA.