Understanding DNA

By Garik Tate
A lot of people assume that every cell in our body does possess human DNA. However closer research has shown us that only about a 3rd of the cells that are in our body has our DNA. The other 2 thirds are bacteria and blood cells (both are substantially smaller cells than the others that make up the human anatomy). But of course this doesn't mean that DNA is any less important. I just thought it was something a lot of people didn't know.

Most of the DNA is stored within the nucleus (the HQ of the cell). The nucleus is a membrane enclosed organelle (the organs of the cell). Most of the mass of the nucleus isn't the DNA itself but rather double membrane that wraps around it (called the nuclear envelope). The nucleus also has things called nuclear pores which allow movement of RNA and various molecules across the envelope.

Many people refer to DNA as the book of life. Sounds like something that you would want to check out at the library right? Well I tried reading it and surprisingly it's not quite as intriguing of a read as you might think. The reason is it only has 4 letters. C (Cytosine), G (Guanine), T (Thymine), and A (Adenine). Yet somehow with such a small alphabet the book of life has more words packed in it then you would think.

These 4 letters are called bases. One type of base can only stick to another base. An Adenine can only match up with a Thymine while a Cytosine can only link up with a Guanine. The bases hook up nucleotides together (a nucleotide is just a sugars and phosphates).

Though a nucleus does contain most of the DNA in a cell. It does not contain all of it. The rest of the DNA within a cell is held in the mitochondria. The mitochondria is seen by me to be like the muscles of the cell. Though technically they do not move the cell they are the powerhouse behind the cell. It is their job to breakdown carbohydrates like glucose into highly energized molecules.

A chromosome is a long DNA molecule (maybe not too long because each one of your cells has around 23 of them and you have trillions of cells in you). It contains hundreds or maybe even thousands of genes. It also has special protein molecules that allow it to maintain its structure.