A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • one year ago

Given DNA structure, would a DNA strand with more adenine and guanine be more stable, or would a DNA strand with more cytosine and thymine be more stable?

  • This Question is Closed
  1. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Are you sure you typed that in correctly? @mathmaticalmolly

  2. Koikkara
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    \(\color{blue}{\huge\tt{DNA ~Structure:}}\)The base–pairs in DNA are adenine-thymine (A-T) and cytosine-guanine (C-G). DNA contains deoxyadenosine (deoxyribose sugar bonded to adenine), deoxyguanosine (deoxyribose sugar bonded to guanine), deoxycytidine (deoxyribose sugar bonded to cytosine), and deoxythymidine (deoxyribose sugar bonded to thymine).

  3. Koikkara
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    \(\color{blue}{\huge\tt{Reference~(in~case)}}\) http://highered.mheducation.com/sites/9834092339/student_view0/chapter14/dna_structure.html

  4. Koikkara
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    \(\color{red}{\huge\tt{Stability:}}\) When working on the structure of DNA, \(\large \mathcal{Watson~ and~ Crick}\), figured out that the two polynucleotides in the DNA (i.e., the DNA strands) interacted through the bases, they also deduced, with the help of Chargraff's rules, that the bases were pretty picky as to whom they interacted with. \(Nucleotides\) containing Adenine (A) would only interact with nucleotides containing Thymine (T), while nucleotides containing Cytosine (C) would only interact with nucleotides containing Guanine (G). \(Which ~Means:\) Only two kinds of base pairs were \(\color{blue}{\large \tt{possible~GC (or CG) and ~AT (or TA)}}\) . So, the two strands of DNA are said to 'complement each other'. This is what we call complementary base pairing. \(Picture:\) Complementary base pairing explains Chargraff's findings. As Adenine always associates with Thymine, the number of As and Ts in DNA must always be the same. You can remember which base associates with which by using the mnemonic GCAT. @MathmaticalMolly From this we understand, the pairing between adenine and guanine or cytosine \(and\) thymine will not be stable \(or\) will not be possible. \(Hope~it~was~clear~for~you~!!\)

  5. Koikkara
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    \(\color{blue}{\huge\tt{Nice~}}\) \(\huge\mathcal{to~meet~}\) \(\color{red}{\huge\tt{You~!}}\)

  6. aaronq
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Good information, but you're missing the point that one pair (AT or GC) will be more stable over the other. In one of the attachments you'll see that the GC pair has 3 hydrogen bonds holding them together, while the AT pair only has 2. Because of the larger number of H-bonds, GC pair is more stable. By stable they mean less susceptible for it to break apart/away. The nitrogenous bases (A, G, T ,C) absorb UV light strongly when they're not paired (because of their conjugated (aromatic) structure), but when paired they no longer absorb - this is called the hyperchromic effect. An experiment can be done to show the stability of the GC pair over the AT pair, synthesize two DNA strands of equal GC and AT pair content, you'll see 50% of absorption at one temperature and 50% at the other. The first (lower) temperature will indicate the melting of the A-T pair and the higher temp the GC pair |dw:1443871594366:dw|

  7. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @aaronq Has it absolutely right, which is why I asked if the question is written correctly. A high C-G percentage does provide slightly more heat resistance compared to a DNA strand with a significantly lower C-G percentage.

  8. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.