Structure of the modified nucleoside 2',3'-dideoxy-3'-fluorocytidine

[wwwaazup]

how would i even begin this problem:

Draw the structure of te modified nucleoside 2',3'-dideoxy-3'-fluorocytidine

 

[Renge Ishyo]

First draw the regular nucleoside cytidine. Then make the substitutions on the ribose ring at the mentioned positions to get the modified cytidine.

 

[chemisttree]

And understand the difference between a nucleoside and a nucleotide...

 

[wwwaazup]

so once i draw nucleoside cytidine, do i take both of the bottom OH off and then put a F on the spot i removed the 3' OH??

 

[Moonbear]

This type of question is REALLY hard to help with without pictures. Do you have a scanner that you can upload your attempt at a drawing as a picture or attachment so we can see what you have so far?

Something else to consider as you're trying to make substitutions, think about valence electrons. Which of the atoms around that 3' position is most similar to Fluorine? That's the one that Fluorine is going to replace.

I can see that your whole series of homework questions is trying to get you to think about the chemistry while you're learning about these different biological molecules. Your teacher/professor clearly wants you to understand the relationship between the chemistry and biology and not just learn to match patterns and repeat memorized modifications to the molecules, so my big tip here is to refresh your memory about what types of bonds different atoms like to form, and how many valence electrons they have.

You may or may not have done it already, but I'm predicting from this direction of inquiry that a next step will involve understanding things like partial charges on the whole molecules, which will tell you a lot about how they interact in the big "soup" called a cell. So, put good effort into understanding the concepts here, not just trying to plug groups haphazardly onto molecules until someone says they're in the right place.

 

[Mohammed Amer]

it will be like this:

http://img399.imageshack.us/img399/5053/cytidinesd5.jpg