What factors stabilize the Dna double helix?

Answer 1

Hydrogen bonds between bases.
There are 3 HB between Guanine and citosine. There are two hydrogen bonds between Adenine and guanine. Therefore, if GC content is higher, DNA is more stabile.

Answer 2

Hydrogen bonds are the main stabilizing factors, three between each G/C pair and two between each A/T pair. this is why hydrolysis seperates DNA strands.

There are also weaker stabilizing forces that come from the surrounding bases since the helix positions them on top of one another.

Answer 3

The purine and pyrimidine bases are hydrophobic

and relatively insoluble in water at the near-neutral pH

of the cell. At acidic or alkaline pH the bases become

charged and their solubility in water increases. Hydrophobic

stacking interactions in which two or more

bases are positioned with the planes of their rings parallel

(like a stack of coins) are one of two important

modes of interaction between bases in nucleic acids. The

stacking also involves a combination of van der Waals

and dipole-dipole interactions between the bases. Base

stacking helps to minimize contact of the bases with water,

and base-stacking interactions are very important in

stabilizing the three-dimensional structure of nucleic

acids.

The DNA double helix, or duplex, is held together

by two forces: hydrogen bonding

between complementary base pairs and

base-stacking interactions. The complementarity between

the DNA strands is attributable to the hydrogen

bonding between base pairs. The base-stacking interactions,

which are largely nonspecific with respect to the

identity of the stacked bases, make the major contribution

to the stability of the double helix.

The sugar-phosphate backbone of DNA is polar, and therefore hydrophillic; thus it likes to be proximal to water. The interior portion of DNA, the bases, are relatively non-polar and therefore hydrophobic. This duality has a very stabilizing effect on the overall structure of the DNA double helix: the hydrophobic core of the DNA molecule 'wants' to be hidden inside the sugar-phosphate backbone which acts to isolate it from the polar water molecules. Due to these hydrostatic forces there is a strong pressure gluing the two strands of DNA together.

Answer 4

Hydrogen bonding between complementary bases mostly stabilize the dna helix. This can be seen by adding slight heat, the hydrogen bonds will be disrupted and break. This can be exemplified by the A=T and C#G bonds. There are two hydrogen bonds between A and T, and three H-bonds between C and G. There is a stronger stabilization bonding between C and G and that is the reason the bonds between A and T will break first, it takes more thermal energy (heat) to break the C-G triple bonds.

More important are hydrophobic forces that make the bases orient inside the double helix!

Answer 5

Great Question: Along it's 1.87 meter length (in humans) [per Cell] - considering the difficulty of 'chemical bonding' in regions of closely spaced negative charges - the {2' deoxy} ribose [sugar] - phosphate bond is as strong as it is rigid and brittle and it could not function biochemically without the Histone protein Cores; and

Across It bi-laterally - Hydrogen Bonds [two for the One pair and three for the Other pair] are responsible for the Base Pair commitments and the rewinding and unwinding Processes - via the Principle of [bio]Complementarity.

Answer 6

Just the electromagnetic force, mostly acting in hydrogen bonds and covalent bonds.