Organic Chemistry III
	Professor Carl C. Wamser
Chem 336 - Spring 2007	Quiz 28

1. (3 points) The structure of uric acid is shown below.

Is this a purine or pyrimidine? Purine

Write a tautomer in which all carbonyls are in their enol forms.

2. (3 points) Write a complete structure for GDP (diphosphate on the 5’ position).

3. (4 points) On the structure of cytidine, shown below, show all the sites (anywhere in the molecule) that could act as H-bond acceptors by adding the appropriate lone pairs. Show H atoms that could act as H-bond donors by circling the H atoms (anywhere in the molecule).