Be able to identify the structures for adenosine, adenosine monophosphate, adenosine diphosphate and adenosine triphosphate and to state whether they are nucleosides or nucleotides!
In a previous objective, you learned to identify the purine bases adenine and guanine. You also learned to identify the pyrimidine base thymine. The pyrimidine bases uracil and cytosine are not covered in this chapter.
Here, we are going to cover AMP, ADP, ATP, nucleosides or nucleotides. Please refer to the structure of ATP in the section on Glycosides (Fig 5.16 in third edition).
A nucleoside is a pyrimidine or purine base attached to a ribose or deoxyribose by an N-glycosidic bond. There are no phosphates attached to a nucleoside.
A nucleotide is a nucleoside attached to 1, 2, or 3 phosphate groups.
In the figure, when adenosine is attached to one phosphate, the structure can be referred to as AMP, adenosine monophosphate, and a nucleotide.
When adenosine is attached to two phosphates, the structure can be referred to as ADP, adenosine diphosphate, and a nucleotide.
When adenosine is attached to three phosphates, the structure can be referred to as ATP, adenosine triphosphate, and a nucleotide.
Note that nucleotide refers to AMP, ADP, or ATP.
Note that nucleotides can be named as derivatives of nucleosides by designating how many phosphates are in the molecule (adenosine monophosphate, adenosine diphosphate, adenosine triphosphate).
None of the nucleotides are nucleosides. They are simply named as derivatives of nucleosides.