Full form of DNA
DNA stands for "Deoxyribonucleic acid". DNA is the molecule responsible for transmitting and carrying inherited materials or genetic instructions from parents to children. DNA is an organic compound that has a unique molecular structure. It is found in eukaryotic and prokaryotic cells. Swiss biologist Johannes Friedrich Miescher first recognized and named DNA in 1869 while working on white blood cells. James Watson and Francis Crick later discovered the double helix structure of the DNA molecule using experimental evidence. Finally, it became clear that DNA is responsible for processing a person's genetic information.
One could think of the structure of DNA as a twisted ladder. This structure is defined as a double helix. The basic building blocks of the DNA are nucleotides, which contain a carbon-sugar group, a nitrogenous base and a phosphate group. Sugar and phosphate groups bind the nucleotides together to form each strand of DNA. The four forms of nitrogenous bases are adenine (A), thymine (T), guanine (G), and cytosine (C).
Type of DNA
Different types of DNA are-
- A – DNA
It is a right-handed DNA and the dehydrated DNA takes the form of A form that protects the DNA under the active conditions such as protein binding, desiccation also removes DNA solvent.
- B – DNA
It is the common DNA conformation, which is a right-handed helix. The majority of the DNA has a type B conformation under the physiological conditions.
- Z – DNA
It is a left-handed DNA, where a double helix in a zig-zag pattern winds to the left and the Alexander Rich and the Andres Wang discovered it. It is located ahead of a gene ‘s starting site and is therefore assumed to play a role in controlling the gene.
Functions of DNA
- It is the genetic material that contains all the inherited information encoded in its structure of nitrogenous bases.
- It also passes genetic information from one cell to its daughters, as well as from one generation to the next.
- Each person has their own DNA sequence that does not match the others. This property of DNA is used in DNA fingerprinting, a method used to identify a person from their DNA.
Structure of DNA
DNA is made up of a combination of alternately repeated monomers called nucleotides. Deoxyribonucleic acid can be divided into deoxyribose, a sugar compound, nucleic acid, a phosphate bond, and a base pair. Bases are nucleobases composed of nitrogen, which are connected by hydrogen bonds.
DNA consists of four nucleobases, adenine, cytosine, thymine, and Guanine, designated by the letters of the alphabet, A, C, T, and G. These bases are linked to each other in an alternative pattern, such as adenine combined with thymine hydrogen-bonded. Similarly, Cytosine hydrogen bonds with Guanine.
These base pairs are further combined with the sugar-phosphate backbone. The sugar-phosphate backbone is a bonded sugar-phosphate pair that is present in a twisted chain surrounding base pairs to form the overall structure of DNA, i.e., the double helix.