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Thursday, 16 September 2021


                                   DNA




 DNA was discovered in 1869 by Swiss researcher Friedrich Miescher



Rosalind Franklin -understanding of the molecular structures of DNA,








James Watson and Francis Crick, who discovered the structure of DNA in 1953.




Where is this DNA?

Most  DNA is located in the cell nucleus (where it is called nuclear DNA), but a small amount of DNA can also be found in the mitochondria


Do you know what the name DNA means?   It means deoxyribonucleic acid

Let's talk about that


The structure of DNA

 

 A double helix molecule composed of two polynucleotide chains containing the deoxyribose sugar group


DNA is made up of the elements carbon, hydrogon , oxygen, nitrogen and  phosphorus  .DNA can be divided into three main components

They are 1. Pentose sugar

              2. Nitrogen base

              3.Phosphoric acid / phosphate group

 If you have never heard of this, you may be wondering

 What is a polynucleotide chain?

 The polynucleotide chain is made up of a number of deoxyribonucleotides bound by        phosphodiester bonds.

 A deoxyribonucleotide is a unit made up of the three main components of the .DNA we talked about earlier.

 It can be stated as follows. 

deoxyribonucleotide is the basic structure as well as the regenerative unit of DNA.


.DNA has four different languages

1adenine (A) 2.thymine (T) 3. cytosine 4. guanine (G There are four types of deoxyribonucleotide



 DNA molecule is made up of two chains of polynucleotides formed by the binding of many deoxyribonucleotides to phosphodiester bonds.

Now there are two chains of polynucleotides but 

How do these two polynucleotide chains come together?


 Nitrogen base helps in binding polynucleotide chains.

But there are no bonds between the four nitrogen bases.

They occur between the complementary bases adenine (A) and thymine (T) and between cytosine (C) and guanine (G).

 There are also two hydrogon bonds between adenine (A) and thymine (T)

 There are also three hydrogon bonds between cytosine (C) and guanine (G)


As a result of these bonds, the polynucleotide chains form an interconnected double helix structure.

 


 The group of pentose sugars and phosphates is called the DNA backbone.

Saturday, 14 August 2021