Nucleic are polymers made of monomers called nucleotides. Two types of nucleic acids, DNA (deoxyribonucleic acid) and RNA (ribonucleic acid). Nucleic acids are macromolecules that exists as polymers called polynucleotides.
Polynucleotide consists of monomers called nucleotides which composed of three parts:
Polynucleotide consists of monomers called nucleotides which composed of three parts:
- five-carbon sugar (pentosa sugar)
- a nitrogenous base
- a phosphate group
Sugars
Nitrogenous base
There are two families of these bases:
1. Pyrimidines - has one six-membered ring of carbon and nitrogen atoms. The members of pyrimidines are Cytosine (C), Thymine (T), Uracil (U)
2. Purines - it is larger, having six-membered ring fused to a five membered rings. Memberes of purines are Adenine (A) and Guanine (G)
There are differences between DNA and RNA as shows in the table below:
- in DNA, sugar is deoxyribose
- in RNA, sugar is ribose
Nitrogenous base
There are two families of these bases:
1. Pyrimidines - has one six-membered ring of carbon and nitrogen atoms. The members of pyrimidines are Cytosine (C), Thymine (T), Uracil (U)
2. Purines - it is larger, having six-membered ring fused to a five membered rings. Memberes of purines are Adenine (A) and Guanine (G)
There are differences between DNA and RNA as shows in the table below:
Nucleotide polymers
Nucleotides are joined by phospodiester linkage, which consists of a phosphate group links to sugars of two nucleotides. One end has a phosphate attached to sugars of two nucleotides.
- one end has a phosphate attached to a 5' carbon, the other end has a hydroxyl group on 3' carbon
- the bonding results in a backbone with a repeating pattern of sugar-phosphate units