Nucleotide

From Freepedia

Nucleotide codes

Code	Equivalence	Complement
A	A	T or U
C	C	G
G	G	C
T or U	T	A
M	A or C	K
R	A or G	Y
W	A or T	W
S	C or G	S
Y	C or T	R
K	G or T	M
V	A or C or G	B
H	A or C or T	D
D	A or G or T	H
B	C or G or T	V
X or N	A or C or G or T	X

A nucleotide is a monomer or the structural unit of nucleotide chains forming nucleic acids as RNA and DNA. A nucleotide consists of a heterocyclic nucleobase, a pentose sugar (ribose or deoxiribose), and a phosphate or polyphosphate group. Nucleotides also play important roles in cellular energy transport and transformations (notably ATP and NAD+/NADH), and in enzyme regulation (see for example, protein kinase).

The nucleobase can be purines or pyrimidines, the sugar can be deoxyribose in DNA or ribose in RNA, and the phosphate chain can be a monophosphate, diphosphate, or triphosphate. A nucleotide that lacks the phosphate group is called nucleoside.

Contents 1 Nomenclature 2 Chemical structures 2.1 Nucleotides 2.2 Deoxynucleotides 3 See also 4 External links

Nomenclature

Nucleotide names are abbreviated into standard four-letter codes. The first letter is lower case and indicates whether the nucleotide in question is a ribonucleotide (r) or deoxyribonucleotide (d). The second letter indicates the nucleoside corresponding to the nucleobase:

G: Guanine

A: Adenine

T: Thymine

C: Cytosine

U: Uracil not usually present in DNA, but takes the place of Thymine in RNA

The third and fourth letters indicate the length of the attached phosphate chain (Mono-, Di-, Tri-) and the presence of a phosphate (P).

For example, deoxy-cytidine-triphosphate is abbreviated as dCTP.

Chemical structures

Nucleotides

Image:AMP chemical structure.png Adenosine monophosphate AMP	Image:ADP chemical structure.png Adenosine diphosphate ADP	Image:ATP chemical structure.png Adenosine triphosphate ATP
Image:GMP chemical structure.png Guanosine monophosphate GMP	Image:GDP chemical structure.png Guanosine diphosphate GDP	Image:GTP chemical structure.png Guanosine triphosphate GTP
Image:TMP chemical structure.png Thymidine monophosphate TMP	Image:TDP chemical structure.png Thymidine diphosphate TDP	Image:TTP chemical structure.png Thymidine triphosphate TTP
Image:UMP chemical structure.png Uridine monophosphate UMP	Image:UDP chemical structure.png Uridine diphosphate UDP	Image:UTP chemical structure.png Uridine triphosphate UTP
Image:CMP chemical structure.png Cytidine monophosphate CMP	Image:CDP chemical structure.png Cytidine diphosphate CDP	Image:CTP chemical structure.png Cytidine triphosphate CTP

Deoxynucleotides

Image:DAMP chemical structure.png Deoxyadenosine monophosphate dAMP	Image:DADP chemical structure.png Deoxyadenosine diphosphate dADP	Image:DATP chemical structure.png Deoxyadenosine triphosphate dATP
Image:DGMP chemical structure.png Deoxyguanosine monophosphate dGMP	Image:DGDP chemical structure.png Deoxyguanosine diphosphate dGDP	Image:DGTP chemical structure.png Deoxyguanosine triphosphate dGTP
Image:DTMP chemical structure.png Deoxythymidine monophosphate dTMP	Image:DTDP chemical structure.png Deoxythymidine diphosphate dTDP	Image:DTTP chemical structure.png Deoxythymidine triphosphate dTTP
Image:DUMP chemical structure.png Deoxyuridine monophosphate dUMP	Image:DUDP chemical structure.png Deoxyuridine diphosphate dUDP	Image:DUTP chemical structure.png Deoxyuridine triphosphate dUTP
Image:DCMP chemical structure.png Deoxycytidine monophosphate dCMP	Image:DCDP chemical structure.png Deoxycytidine diphosphate dCDP	Image:DCTP chemical structure.png Deoxycytidine triphosphate dCTP

See also

• Gene
• Genetics
• Chromosome

External links

• Abbreviations and Symbols for Nucleic Acids, Polynucleotides and their Constituents (IUPAC)
• Provisional Recommendations 2004 (IUPAC)