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Kaplan Qbank USMLE



Author17 Posts
  #1

can u describe it,i am not able to understand it??

  #2

A palindrome is just a set of duplex DNA that yields the same nucleotide sequence if one turns the helix by 180 degrees about the "centre" of that region. In other words, placing an axis in the middle of the sequence and rotating 180 degrees will yield superimposing images.

G T T A A C
----- -- ------
C A A T T G

Rotate at a point between the central A and T.

  #3

This may be a little out of context, but in laymans terms palindrome means spelling the same thing forwards or backwards--like the word radar.
Hope this helps

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Smell the coffee! "Is That an Osler move??"

  #4

very useful comment, mjl1717!......made me picture it easier. smiling face

is there any clinical application of this concept? for me it's the first time i hear about it and i dont know more ....

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  #5

mj, palindrome is not like sakaki describes it, correct?
'Cuz I was under the same impression as u explain...that the code is the same L :arrow: R or R :arrow: L

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  #6

I've seen palindrome used in the context of a word that reads the same from left to right and vice versa (ex. MOM), but in molecular genetics, I'm pretty sure that what I stated earlier is what palindromes refer to.

Edit: I checked in An Introduction to Genetic Analysis (Griffiths et al), and it states that "a DNA palindrome ... means that both strands have the same nucleotide sequence but in antiparallel orientation. Many different restriction enzymes recognize and cut specific palindromes."

I'm quite sure that that would have more clinical application (at least in genetic analysis) than a word that reads the same in either direction. ^_^

  #7

Sakaki is correct . I just tried to facilitate other people in understanding what it actually means. [Because its one thing to have a definition of something, but something completely different (like Plato or Aristotle) explaining and consciously making sure someone else has complete grasp of a new concept]

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Smell the coffee! "Is That an Osler move??"

  #8

Friends,
Small peice of advice though not required :wink: ....just know what r palindromes and sticky ends and try to do examples for it, that is enough for exam .

  #9

Thanks for the heads-up, asmi. wink

  #10

The sequences in the two strands of the recognition sites are "palindromes",having the same 5' to 3' sequence in both strands.Most restriction nucleases recognize sites consisting four to eight base pairs.Based on site of recognition,fragment will end up as a sticky end or blunt ends with no unpaired tails.

  #11

can anyone explain with an example please ..

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"Read Repeat Recall Remember Recognise & Reproduce"

  #12

3' :arrow: :arrow: 5' direction
CGACTGNNNNNCAGTCG
5' :arrow: :arrow: 3' Direction
GCTGACNNNNNGTCAGC

Palindrome = the sequence on one strand reading 5 to 3 is the same as the sequence on the complementary strand reading in the same direction. So if you read the top two in 5 to 3, they are the same. This helps in stabilization during transcription. Hope this helps!

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"If He takes you to it, He'll take you through it."

  #13

Thanks everyone, I have never heard about PALINDROME.

Rita thanks, what you mean is
one segment of DNA that are identical sequences of bases run in opposite directions.

Ex 1 2 3 4 5 6 7 8 9
9 8 7 6 5 4 3 2 1

That's what you mean RITA?

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Ruben sssss

  #14

Yes ruben, exactly!!!

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"If He takes you to it, He'll take you through it."

  #15

1 2 3 4 5 6 7 8 9
9 8 7 6 5 4 3 2 1

I can put it like it should.

___________________
Ruben sssss

  #16

Many many thanks ....to everyone!!!

___________________
"Read Repeat Recall Remember Recognise & Reproduce"

  #17

Thanx a lot everyone!
u made it very easy for me.







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