Nucleotides are the basic unit of nucleic acids. They are the building blocks or monomers of DNA and RNA. They link with each other to form a polynucleotide chain, which gives the structure to DNA or RNA. There are three main components in a nucleotide. They are a nitrogenous base, a pentose sugar (five carbon sugar) and phosphate groups. There are five different nitrogenous bases as Adenine, Thymine, Cytosine, Guanine and Uracil. Thymine is seen only in DNA, while uracil is unique to RNA. There are two types of five carbon sugars in nucleic acids. RNA contains ribose sugar while DNA contains deoxyribose sugar. Nucleotides contain three phosphate groups attached to the pentose sugar.
1. Overview and Key Difference
2. What is a DNA Nucleotide
3. What is an RNA Nucleotide
4. Similarities Between DNA and RNA Nucleotide
5. Side by Side Comparison – DNA vs RNA Nucleotide in Tabular Form
What is a DNA Nucleotide?
DNA nucleotide, also known as deoxyribonucleotide, is the basic unit of DNA. DNA nucleotides bind with each other via phosphodiester bonds and form polynucleotide sequences. Deoxyribonucleotide consists of five carbon sugar deoxyribose. Moreover, it contains four types of nitrogenous bases; adenine (A), guanine (G), cytosine (C), and thymine (T). It also has a phosphate group attached to pentose sugar.
De novo synthesis of deoxyribonucleotide requires an enzyme called ribonucleotide reductase (RNR). The formation takes place from ribonucleotide. Apart from that, deoxyribonucleotides may be derived from dietary sources as well. There are four types of deoxyribonucleotides as ATP, CTP, GTP and TTP. Moreover, deoxyribonucleotides can be monophosphates, diphosphates or triphosphates depending on the number of phosphate groups.
What is an RNA Nucleotide?
RNA nucleotide, also known as ribonucleotide, is the monomer or building block of RNA. The sugar component of ribonucleotide is ribose sugar. Moreover, ribonucleotide has one of four nitrogenous bases: adenine (A), guanine (G), cytosine (C), and uracil (U). In RNA, adenine forms hydrogen bonds with uracil, unlike in DNA.
Ribonucleotide reduces into deoxyribonucleotide by the enzyme ribonucleotide reductase. Furthermore, ribonucleotides can be converted into ATP, which is the energy currency of cells or into cyclic AMP. Similar to deoxyribonucleotide, ribonucleotides can be synthesized de novo.
What are the Similarities Between DNA and RNA Nucleotide?
- DNA and RNA nucleotides have three main components: a five-carbon sugar, a phosphate group, and a nitrogenous base.
- They are the building blocks of nucleic acids.
- Ribonucleotide reductase enzyme reduces ribonucleotides to deoxyribonucleotides.
- Both deoxyribonucleotides and ribonucleotides form nucleotide chains via the formation of phosphodiester bonds.
- Both types of nucleotides can be synthesized by de novo pathways.
What is the Difference Between DNA and RNA Nucleotide?
Deoxyribonucleotide is the building block of DNA that has deoxyribose as its sugar component. But, ribonucleotide is the monomer of RNA that has ribose as its sugar component. So, this is the key difference between DNA and RNA nucleotide. Besides, DNA nucleotides have four types of nitrogenous bases as adenine (A), guanine (G), cytosine (C), and thymine (T) while ribonucleotides have adenine (A), guanine (G), cytosine (C), and uracil (U).
Moreover, in DNA nucleotides, we can see two types of base pairs; Adenine and Thymine pair (A-T) and Cytosine and Guanine pair (C-G). In RNA, we can see Adenine and Uracil pair (A-U) and Cytosine and Guanine pair (C-G).
Below infographic summarizes the difference between DNA and RNA nucleotide.
Summary – DNA vs RNA Nucleotide
DNA and RNA nucleotides are the building blocks of DNA and RNA, respectively. The key difference between DNA and RNA nucleotide lies on the pentose sugar each contains. DNA nucleotide has deoxyribose sugar while RNA nucleotide has ribose sugar. Moreover, DNA nucleotide has one of four types of A, T, C and G nitrogenous bases while RNA nucleotide has one of four types of A, U, C and G. Both types can be synthesized de novo pathways.
1. “DNA chemical structure” By Madprime (talk · contribs) – Own work – The source code of this SVG is valid. This vector image was created with Inkscape (CC BY-SA 3.0) via Commons Wikimedia
2. “Ribonucleotide General” By Binhtruong – Own work (CC BY-SA 3.0) via Commons Wikimedia