Home >
Community >
Why are nitrogenous bases of DNA hydrophobic if they can hydrogen bond?
Upvote
20
Downvote
+ Dna
+ Pharma
+ Genetics
+ Biochemistry
Posted by
Kamran Fateh
Why are nitrogenous bases of DNA hydrophobic if they can hydrogen bond?
These two concepts are not mutually exclusive. You have constructed a false dichotomy. Both of these facts are true:
The electrons in the pi orbitals of the conjugated double bonds in the planar rings are hydrophobic and can "stack" on each other as shown in this drawing of a DNA helix where the bases are shown as planar rectangles:
The nitrogen and oxygen molecules (either in the rings, or as substituents on the rings) can participate in hydrogen bonds (H-bonds):
There are other examples of hydrophobicity and H-bonds co-existing. For example on the interior of proteins.
These two concepts are not mutually exclusive. You have constructed a false dichotomy. Both of these facts are true:
The electrons in the pi orbitals of the conjugated double bonds in the planar rings are hydrophobic and can "stack" on each other as shown in this drawing of a DNA helix where the bases are shown as planar rectangles:
The nitrogen and oxygen molecules (either in the rings, or as substituents on the rings) can participate in hydrogen bonds (H-bonds):
There are other examples of hydrophobicity and H-bonds co-existing. For example on the interior of proteins.
I think the confusion here is that no, the DNA bases aren't in themselves completely hydrophobic, but in the region of the planar face of each base is a zone of hydrophobicity. In this way, base stacking becomes favorable where water molecules would otherwise attempt to order themselves to maximize hydrogen bonding with each other.More
These two concepts are not mutually exclusive. You have constructed a false dichotomy. Both of these facts are true:
There are other examples of hydrophobicity and H-bonds co-existing. For example on the interior of proteins.
These two concepts are not mutually exclusive. You have constructed a false dichotomy. Both of these facts are true:
There are other examples of hydrophobicity and H-bonds co-existing. For example on the interior of proteins.
More
VOTE
VOTE
VOTE
VOTE
VOTE
VOTE