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Score for this quiz: 5 out of 5 B)OCHEM MOD b QU/Z
Submitted
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This attempt took 43 minutes.
Question 1
0/0pts
What is the difference between a nucleoside and nucleotide?
Your Answer:
ale ntl y bo nd ed to eit her rib ose or 2- de ox yr ib os e.
Nucleosides consist of base, purine or pyrimidine, cov
Nucleotides are built from a base, a monosaccharide (sugar), and phosphoric acid.
Essentially, a nucleotid e is a nuc leo sid e wit h a ph os ph at e gro up att ach ed to it.
co va le nt bo nd in g of a bas e, pur ine or py ri mi di ne , to eit her
A nucleoside is formed from the
are bui lt fro m a ni tr og en -c on ta in in g or ga ni c bas e, a
ribose or 2-deoxyribose. Nucleotides
monosaccharide, and phosphate.
Question 2
0/0pts
What cha rac ter ist ic ma ke s pur ine s and pyr imi din e het ero cyc lic ?
Your Answer:
Their ring structures contain ato ms fro m at leas t two dif fer ent ele men ts (ca rbo n and nit rog en) , not sol ely
carbon atoms.
Each has a ring with nitr og en in th e ri ng in st ea d of all ca rb on at om s in th e ri ng .
Question 3
0/0pts
Is this molecule ribo se or 2-d eox yri bos e? Brie fly expl ain what stru ctur al info rmat ion was used to
determine this.
, J 0 OH
,,, - .
H H
OH OH
Your Answer:
This molecule is ribose, as evidenced by the -OH atta
ched to carbon 2. Deoxyribose would have an -H
attached to carbon 2.
Ribose. This molecule contains an -OH on
carbon 2. 2-deoxyribose has an -H atom on the second
carbon.
Question 4
0/0pts
Is the following a pyrimidine or purine? Provide the name and one-letter sym
bol.
(0]
I NH
N/KO
H
Your Answer:
Pyrimidine.
Thymine (T)
Pyrimidine. It is thymine (T).
Question 5
0/0npts
What is the difference between thymine and uracil?
Your Answer:
Thymine is found only in DNA, and Uracil is found only in RNA.
These two bases differ by a methyl group. Thymine has an extra methyl group on the ring.