DNA, or deoxyribonucleic acid, is the molecule that contains the genetic information for all living things. DNA is like a blueprint for life - it tells the cells in our bodies how to function and grow.
Every person has a unique DNA sequence, which is why DNA is used in forensics and paternity testing. DNA is made up of four chemical bases: adenine (A), thymine (T), guanine (G), and cytosine (C). These bases are arranged in pairs, and the sequence of these pairs makes up the DNA code.
How is the DNA stored?
In the body, DNA is stored in the nucleus of cells. The DNA is wrapped around proteins called histones, which help to keep the DNA organized and protected. The DNA is coiled up very tightly, so that it can fit inside the cell nucleus.
This tightly coiled DNA is called chromatin, and the individual chromosomes that we inherit from our parents are made up of chromatin. When cells divide, the DNA is uncoiled and copied so that each new cell will have its own copy of the DNA.
There are three different DNA types:
A-DNA: It is a right-handed double helix similar to the B-DNA form. Dehydrated DNA takes an A form that protects the DNA during extreme conditions such as desiccation. Protein binding also removes the solvent from DNA, and the DNA takes an A form.
B-DNA: This is the most common DNA conformation and is a right-handed helix. The majority of DNA has a B type conformation under normal physiological conditions.
Z-DNA: Z-DNA is a left-handed DNA where the double helix winds to the left in a zig-zag pattern. It was discovered by Andres Wang and Alexander Rich. It is found ahead of the start site of a gene and hence, is believed to play some role in gene regulation.
Structure of the DNA
The DNA structure can be thought of as a twisted ladder. This structure is described as a double-helix, as illustrated in the figure above. DNA nucleic acid, and all nucleic acids are made up of nucleotides.