Chem 210 Module 6 Exam Newest
1.What is the difference between a nucleoside and nucleotide?: A nucleoside is formed
from the covalent bonding of a base (purine or pyrimidine) to either ribose (RNA) or 2-
deoxyribose (DNA). Nucleotides are built from a nitrogen-containing organic base, a
monosaccharide, and phosphate.
2.What characteristic makes purines and pyrimidine heterocyclic?: Each has a ring
with nitrogen in the ring instead of all carbon atoms in the ring.
3.Is this molecule ribose or 2-deoxyribose? Briefly explain what structural
information was used to determine this.: Ribose. This molecule contains an -OH on carbon
2. 2-deoxyribose has an -H atom on the second carbon.
4.Is the following a pyrimidine or purine? Provide the name and one-letter
symbol.: Pyrimidine. It is thymine (T).
5.What is the difference between thymine and uracil?: These two bases differ by a
methyl group. Thymine has an extra methyl group on the ring.
6.From the course and module information, where in a eukaryotic or prokary- otic
cell, is the DNA located? How about the RNA?: DNA is located in the nucleus of a
eukaryotic cell or the nucleoid of a prokaryotic cell. RNA is found in the nucleus, on the
ribosome, and in other parts of the cell.
