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Thymine

 

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Thymine



 
 
Thymine is one of the four bases in the nucleic acid
Nucleic acid

A nucleic acid is a macromolecule composed of chains of monomeric nucleotides. In biochemistry these molecules carry genetic information or form structures within Cell ....
 of DNA
DNA

Deoxyribonucleic acid is a nucleic acid that contains the genetics instructions used in the development and functioning of all known living organisms and some viruses....
 that make up the letters GCAT. The others are adenine
Adenine

Adenine is a nucleobase with a variety of roles in biochemistry including cellular respiration, in the form of both the energy-rich adenosine triphosphate and the cofactor s nicotinamide adenine dinucleotide and flavin adenine dinucleotide , and Protein biosynthesis, as a chemical component of DNA and RNA....
, guanine
Guanine

Guanine is one of the five main nucleobases found in the nucleic acids DNA and RNA, the others being adenine, cytosine, thymine, and uracil. In DNA, guanine is paired with cytosine....
, and cytosine
Cytosine

Cytosine is one of the five main bases found in DNA and RNA. It is a pyrimidine derivative, with a heterocyclic aromatic ring and two substituents attached ....
. Thymine (T) always pairs with adenine. Thymine is also known as 5-methyluracil, a pyrimidine
Pyrimidine

Pyrimidine is a heterocyclic aromatic organic compound similar to benzene and pyridine, containing two nitrogen atoms at positions 1 and 3 of the six-member ring....
 nucleobase
Nucleobase

Nucleobases are the parts of DNA and RNA that may be involved in pairing . The main ones are cytosine, guanine, adenine , thymine and uracil , abbreviated as C, G, A, T, and U, respectively....
. As the name suggests, thymine may be derived by methylation of uracil at the 5th carbon. In RNA
RNA

Ribonucleic acid is a type of molecule that consists of a long chain of nucleotide units. Each nucleotide consists of a nucleobase, a ribose sugar, and a phosphate....
, thymine is replaced with uracil
Uracil

Uracil is a common and naturally occurring pyrimidine derivative. Originally discovered in 1900, it was isolated by hydrolysis of yeast nuclein that was found in bovine thymus and spleen, herring, sperm, and wheat germ....
 in most cases. In DNA, thymine(T) binds to adenine
Adenine

Adenine is a nucleobase with a variety of roles in biochemistry including cellular respiration, in the form of both the energy-rich adenosine triphosphate and the cofactor s nicotinamide adenine dinucleotide and flavin adenine dinucleotide , and Protein biosynthesis, as a chemical component of DNA and RNA....
 (A) via two hydrogen bonds to assist in stabilizing the nucleic acid structures.

Thymine combined with deoxyribose
Deoxyribose

Deoxyribose, also known as D-Deoxyribose and 2-deoxyribose, is an aldopentose — a monosaccharide containing five carbon atoms, and including an aldehyde functional group in its linear structure....
 creates the nucleoside
Nucleoside

Nucleosides are glycosylamines consisting of a nucleobase bound to a ribose or deoxyribose sugar. Examples of these include cytidine, uridine, adenosine, guanosine, thymidine and inosine....
 deoxythymidine, which is synonymous with the term thymidine
Thymidine

Thymidine is a chemical Chemical compound, more precisely a pyrimidine deoxynucleoside. Deoxythymidine is the DNA nucleoside T, which pairs with deoxyadenosine in double-stranded DNA....
.






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Encyclopedia


Thymine is one of the four bases in the nucleic acid
Nucleic acid

A nucleic acid is a macromolecule composed of chains of monomeric nucleotides. In biochemistry these molecules carry genetic information or form structures within Cell ....
 of DNA
DNA

Deoxyribonucleic acid is a nucleic acid that contains the genetics instructions used in the development and functioning of all known living organisms and some viruses....
 that make up the letters GCAT. The others are adenine
Adenine

Adenine is a nucleobase with a variety of roles in biochemistry including cellular respiration, in the form of both the energy-rich adenosine triphosphate and the cofactor s nicotinamide adenine dinucleotide and flavin adenine dinucleotide , and Protein biosynthesis, as a chemical component of DNA and RNA....
, guanine
Guanine

Guanine is one of the five main nucleobases found in the nucleic acids DNA and RNA, the others being adenine, cytosine, thymine, and uracil. In DNA, guanine is paired with cytosine....
, and cytosine
Cytosine

Cytosine is one of the five main bases found in DNA and RNA. It is a pyrimidine derivative, with a heterocyclic aromatic ring and two substituents attached ....
. Thymine (T) always pairs with adenine. Thymine is also known as 5-methyluracil, a pyrimidine
Pyrimidine

Pyrimidine is a heterocyclic aromatic organic compound similar to benzene and pyridine, containing two nitrogen atoms at positions 1 and 3 of the six-member ring....
 nucleobase
Nucleobase

Nucleobases are the parts of DNA and RNA that may be involved in pairing . The main ones are cytosine, guanine, adenine , thymine and uracil , abbreviated as C, G, A, T, and U, respectively....
. As the name suggests, thymine may be derived by methylation of uracil at the 5th carbon. In RNA
RNA

Ribonucleic acid is a type of molecule that consists of a long chain of nucleotide units. Each nucleotide consists of a nucleobase, a ribose sugar, and a phosphate....
, thymine is replaced with uracil
Uracil

Uracil is a common and naturally occurring pyrimidine derivative. Originally discovered in 1900, it was isolated by hydrolysis of yeast nuclein that was found in bovine thymus and spleen, herring, sperm, and wheat germ....
 in most cases. In DNA, thymine(T) binds to adenine
Adenine

Adenine is a nucleobase with a variety of roles in biochemistry including cellular respiration, in the form of both the energy-rich adenosine triphosphate and the cofactor s nicotinamide adenine dinucleotide and flavin adenine dinucleotide , and Protein biosynthesis, as a chemical component of DNA and RNA....
 (A) via two hydrogen bonds to assist in stabilizing the nucleic acid structures.

Thymine combined with deoxyribose
Deoxyribose

Deoxyribose, also known as D-Deoxyribose and 2-deoxyribose, is an aldopentose — a monosaccharide containing five carbon atoms, and including an aldehyde functional group in its linear structure....
 creates the nucleoside
Nucleoside

Nucleosides are glycosylamines consisting of a nucleobase bound to a ribose or deoxyribose sugar. Examples of these include cytidine, uridine, adenosine, guanosine, thymidine and inosine....
 deoxythymidine, which is synonymous with the term thymidine
Thymidine

Thymidine is a chemical Chemical compound, more precisely a pyrimidine deoxynucleoside. Deoxythymidine is the DNA nucleoside T, which pairs with deoxyadenosine in double-stranded DNA....
. Thymidine can be phosphorylated with one, two, or three phosphoric acid groups, creating, respectively, TMP, TDP, or TTP (thymidine mono-, di-, or triphosphate).

One of the common mutations of DNA involves two adjacent thymines or cytosine, which, in presence of ultraviolet light
Ultraviolet

Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than x-rays, in the range 400 nanometer to 10 nm, and energies from 3 Electron volt to 124 eV....
, may form thymine dimers, causing "kinks" in the DNA molecule that inhibit normal function.


Thymine could also be a target for actions of 5-fluorouracil
Fluorouracil

Fluorouracil is a pyrimidine analog, which is used as a medication in the treatment of cancer. It belongs to the family of drugs called antimetabolites....
 (5-FU) in cancer
Cancer

Cancer is a class of diseases in which a group of cell display uncontrolled growth , invasion , and sometimes metastasis . These three malignant properties of cancers differentiate them from benign tumors, which are self-limited, do not invade or metastasize....
 treatment. 5-FU can be a metabolic analog of thymine (in DNA synthesis) or uracil (in RNA synthesis). Substitution of this analog inhibits DNA synthesis in actively-dividing cells.

Thymine bases are frequently oxidized to hydantoins over time after the death of an organism.

See also

  • deoxyribose
    Deoxyribose

    Deoxyribose, also known as D-Deoxyribose and 2-deoxyribose, is an aldopentose — a monosaccharide containing five carbon atoms, and including an aldehyde functional group in its linear structure....
  • pyrimidine
    Pyrimidine

    Pyrimidine is a heterocyclic aromatic organic compound similar to benzene and pyridine, containing two nitrogen atoms at positions 1 and 3 of the six-member ring....
  • nucleobase
    Nucleobase

    Nucleobases are the parts of DNA and RNA that may be involved in pairing . The main ones are cytosine, guanine, adenine , thymine and uracil , abbreviated as C, G, A, T, and U, respectively....
  • deoxythymidine


  • uracil
    Uracil

    Uracil is a common and naturally occurring pyrimidine derivative. Originally discovered in 1900, it was isolated by hydrolysis of yeast nuclein that was found in bovine thymus and spleen, herring, sperm, and wheat germ....


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