Molecule Tutorials - Herong's Tutorial Examples - v1.26, by Herong Yang
What Is Nucleobase
This section provides a quick introduction of the 5 primary nucleobases: Adenine (A), Cytosine (C), Guanine (G), Thymine (T) and Uracil (U).
What Is Nucleobase? - Nucleobases, also known as nitrogenous bases or often simply bases, are nitrogen-containing biological compounds that form nucleosides, which in turn are components of nucleotides, which is turn are used to build DNA and RNA.
There are only 5 primary nucleobases:
1. Adenine (A) - Adenine (6-Adminopurine), C5H5N5, is a purine type of nucleobase, containing two rings of alternating carbon and nitrogen atoms. Adenine (A) always pairs with Thymine (T) to form an A-T pair.
2. Cytosine (C) - Cytosine (2-Oxo-4-adminopyrimidine), C4H5N3O, is a pyrimidine type of nucleobase, consisting a single ring. Cytosine (C) always pairs with Guanine (G) to form a G-C pair as a building block for DNA.
3. Guanine (G) - Guanine (2-Amino-6-oxopurine), C5H5N5, is a purine type of nucleobase, containing two rings of alternating carbon and nitrogen atoms. Guanine (G) always pairs with Cytosine (C) to form a G-C pair as a building block for DNA.
4. Thymine (T) - Thymine (2,4-Dioxo-5-methylpyrimidine), C5H6N2O2, is a pyrimidine type of nucleobase, consisting a single ring. Thymine (T) always pairs with Adenine (A) to form an A-T pair as a building block for DNA.
5. Uracil (U) - Uracil (2,4-Dioxopyrimidine), C4H4N2O2, is a pyrimidine type of nucleobase, consisting a single ring. Uracil (U) is a building block for RNA.
Here are the molecule structures of the 5 primary nucleobases:
There are also non-primary nucleobases. For example, Hypoxanthine (I), C5H4N, is a modified Adenine (A). And Xanthine (X) is a modified Guanine (G).
Table of Contents
Molecule Names and Identifications
►Nucleobase, Nucleoside, Nucleotide, DNA and RNA
What Is RNA (Ribonucleic Acid)
What Is DNA (Deoxyribonucleic Acid)
DNA Primary Structure - Double Helix
What Is DNA/RNA Base and Sequence Pair
ChEMBL Database - European Molecular Biology Laboratory
PubChem Database - National Library of Medicine
INSDC (International Nucleotide Sequence Database Collaboration)
HGNC (HUGO Gene Nomenclature Committee)