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FRIEDHELM HILDEBRANDT
tural elements, the nucleotides. This is followed in order of increasing complexity, by descriptions of the double stranded structure of DNA, nucleosomes, the structure of chromosomes and the full set of chromosomes. Finally, some functional aspects of the human genome are outlined.
Nucleotides
Nucleotides are composed of a nitrogenaus base, a sugar, and a phosphate.
• Nitrogenaus bases (Figure 2A): purines: Adenine (A), Guanine (G); pyrimidines: Cytosine (C), Thymine (T) (RNA: Uracil (U)); uncommon
bases: dA, m 5 C
• Sugar: 2' -deoxyribose (DNA), ribose (RNA)
• Mono-, di-, triphosphate residue
A schematic of the composition of nucleotides is given in Figure 2B:
nitrogenaus base + sugar = nucleoside ( e.g. adenine +ribose = adenosine)
nucleoside + phosphate = nucleotide (e.g. adenosine +mono-, di-, tri-phosphate =adenosine-mono-, di-, tri-phosphate (AMP, ADP, ATP)
Nucleotides are the primary building blocks of the nucleic acids DNA
and RNA. For the nomenclature of nucleotides see Table 1.
Table 1. Nomenclature of nucleic acids
Base
Nucleoside
Nucleotide
Abbreviation
RNA
DNA
Adenine
adenosine
adenylic acid
AMP
dAMP
Guanine
guanosine
guanylic acid
GMP
dGMP
Cytosine
cytidine
cytidylic acid
CMP
dCMP
Thymine
thymidine
thymidylic acid
dTMP
Uracil
uridine
uridylic acid
UMP
FRIEDHELM HILDEBRANDT
tural elements, the nucleotides. This is followed in order of increasing complexity, by descriptions of the double stranded structure of DNA, nucleosomes, the structure of chromosomes and the full set of chromosomes. Finally, some functional aspects of the human genome are outlined.
Nucleotides
Nucleotides are composed of a nitrogenaus base, a sugar, and a phosphate.
• Nitrogenaus bases (Figure 2A): purines: Adenine (A), Guanine (G); pyrimidines: Cytosine (C), Thymine (T) (RNA: Uracil (U)); uncommon
bases: dA, m 5 C
• Sugar: 2' -deoxyribose (DNA), ribose (RNA)
• Mono-, di-, triphosphate residue
A schematic of the composition of nucleotides is given in Figure 2B:
nitrogenaus base + sugar = nucleoside ( e.g. adenine +ribose = adenosine)
nucleoside + phosphate = nucleotide (e.g. adenosine +mono-, di-, tri-phosphate =adenosine-mono-, di-, tri-phosphate (AMP, ADP, ATP)
Nucleotides are the primary building blocks of the nucleic acids DNA
and RNA. For the nomenclature of nucleotides see Table 1.
Table 1. Nomenclature of nucleic acids
Base
Nucleoside
Nucleotide
Abbreviation
RNA
DNA
Adenine
adenosine
adenylic acid
AMP
dAMP
Guanine
guanosine
guanylic acid
GMP
dGMP
Cytosine
cytidine
cytidylic acid
CMP
dCMP
Thymine
thymidine
thymidylic acid
dTMP
Uracil
uridine
uridylic acid
UMP