dna unusual structures

[bebe1018_87]

i have to fill in the blanks for the following questions using the following choices (some will be used once, others more than once, and others not at all) : z-dna, cruciform structure, mirror repeat, hairpin structure, g-tetraplex, triplex dna, hoogsteen pairs, a-dna, duplex dna, inverted repeat.

 

1. A(n) ____ does not have complementary sequence on the same strand.

 

2. a(n) _________ is self-complementary.

 

3. a sequence, such as a palindrome, that can be rotated 180 degrees horizontally and 180 vertically in order to superimpose a sequence repeat on the other sequence is a(n):__________

 

4. a four-stranded, right-handed helix formed by a dna segment containing a high proportion of guanine residues is known as a(n)_______________

 

5. in a(n) _____________, interstrand hydrogen bonds break and intrastrand hydrogen bonds form.

 

6. an inverted repeat that occurs within a single dna strand is a(n)_________

 

7. the sequence -GTGAG........CTCAC-

-CACTC.........GAGTG- is a(n)_____________ and has the potential to form a(n)______________.

 

8. _____________ can form when a polynucleotide strand forms ___________ with functional groups in the major groove of a homopurine-homopyrimidine duplex that can contain a mirror repeat.

 

9. a single dna strand with the sequence-ATATG.....CATAT-can form a(n) ______________.

 

the hint given is a mirror repeat has symmetry such that folding the sequence back onto itself superimposes the bases. however, then folding the the sequence onto the opposite strand does not superimpose the bases. consider whether a mirror repeat has a superimposable sequence in the complementary strand.

 

thank you so much for your help!

 

 

My answers were the following but some are incorrect:

1. mirror repeat

2. duplex dna

3. mirror repeat

4. g-tetraplex

5. hairpin structure

6. mirror repeat

7. inverted, cruciform structure

8. triplex dna, hoogsteen pairs

9. hairpin structure

 

 

Thank you !

Edited October 18, 2010 by bebe1018_87

[jimmydasaint]

Ahem...You do know you cannot get direct answers to your question. I think you need to do a bit of light reading. If you have problems, please reply and I will try to check up on your reply.

 

First Link If you find this too difficult, try the second link:

 

Link 2

 

 

Hope this helps