Nucleic Acid Structure and General Features

ID #1061

If a base + sugar is a nucleoside, and a base + sugar + phosphate is a nucleotide, why is a nucleoside + 1 phosphate called a nucleoside monophosphate? Doesn't it become a nucleotide when a phosphate is added to the base and sugar?

You're on the right track. When you add a phosphate (or 2 or 3) to a base and a sugar, it is in fact now called a nucleotide. You're right about that part. But that's all you would call it -- a nucleotide. And that term doesn't tell anyone how many phosphate groups it has attached to it, which is very relevant information for what you might be able to do with that nucleotide. So you can go back to a previous level of naming with just the base and sugar--a nucleoside group--and then identify how many phosphates are attached to it. A nucleoside monophosphate is a nucleotide, but a nucleotide isn't necessarily a nucleoside monophosphate, if you see what I mean.

Print this record Print this record
Send to a friend Send to a friend
Show this as PDF file Show this as PDF file
Export as XML-File Export as XML-File