2. DNA is one of a class of nucleic acids. You may wonder, "What is a
Nucleic acid?". Well, they are large biological molecules often called
Macromolecules. Macromolecules are commonly created by
polymerization.
DNA's were first found in Pus cells, a thick liquid produced from
infected tissues. Friedrich Meischer was the first to isolate(A
combination of physical and chemical methods for DNA purification
from samples) DNA.
DNA and it’s history
3. Like every molecules, DNA's have building blocks. Those are called
Nucleotides. There are four of them.
oAdenine
oCytosine
oGuanine
oThymine
DNA Building blocks
4. Every nucleotides have also 3 components like
oDeoxyribose
oPhosphate group
oNitrogenous base Nitrogenous base can be two kinds
• Purine(double ringed base)
• Pyrimidine(single ringed base)
Nucleotide component
5. The nucleotides Adenine and Guanine are Purine based. The other
two are Pyrimidine based.
The phosphate groups form the strand of DNA and the bases connect
two nucleotides from two strands(double helix DNA). Deoxyriboses
situate at the center
Nucleotide Structure
