MoBio Cellular Nucleotides and Nucleosides Chapter 3

In cells, a free nucleotide may contain one, two or three phosphate groups. The energy carrier ATP (adenosine triphosphate) has three phosphate groups; ADP (adenosine diphosphate) has two; AMP (adenosine monophosphate) has one. Their structures are shown in the following figure.

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Figure 3-A-4. (a) A computer model of AMP. (b) Chemical structures of Adenosine, ADP and ATP. They differ in the number of phosphate groups.

If all phosphate groups are removed, a nucleotide becomes a nucleoside such as adenosine. The following table lists various nucleosides and nucleotides.

Table 3-A-1. Cellular nucleosides and nucleotides.

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NMP = nucleoside monophosphate
NDP = nucleoside diphosphate
NTP = nucleoside triphosphate
dNMP = deoxynucleoside monophosphate
dNDP = deoxynucleoside diphosphate
dNTP = deoxynucleoside triphosphate

(nucleoside = ribonucleoside; deoxynucleoside = deoxyribonucleoside).