Question

In how many different ways can different nitrogen bases in a pair form at least two hydrogen bonds? Justify why only A and T as well as G and C form stable pairs.

Answer 1

http://www.google.co.in/imgres?imgurl=http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/B/BasePairing.gif&imgrefurl=http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/B/BasePairing.html&h=274&w=255&sz=5&tbnid=wb7Id-PdSSqiPM:&tbnh=90&tbnw=84&zoom=1&usg=__Up-tO7NAXfdlTCZm1s4XmWc68cE=&docid=EdnV6MmDGKIUEM&sa=X&ei=zvLcUamtIoXsrAeHsoCYAw&ved=0CEkQ9QEwAw&dur=2386

look at this diagram

Answer 2

Hydrogen bonds are formed between A and T and similarly between G and C

as it should be clear from the diagram, complete stable arrangement or max H-bonds are formed between A and T (i.e. there is no leftover N or O that could form H bond)

Answer 3

If A and C forms H bonds,
there would be 2 hydrogen bonds forming
and it wont be stable as it would look for 1 more H bond formation

Answer 4

Okay. How many hydrogen bonds would be in the pair G-T?

Answer 5

2 only

A and T are capable of forming 2 bonds
G and C can form 3 bonds

Answer 6

Oh, got it now. Thank you so much. (:

Answer 7

welcome :)