2006-09-17 02:41:59 · 9 answers · asked by dconstruct6 1 in Science & Mathematics ➔ Biology
DNA is not a spiral. DNA is a double helix.
It is due to the intermolecular forces between the phosphorous atoms with the amino acids that causes the double helix formation.
2006-09-17 02:45:22 · answer #1 · answered by Allen G 3 · 0⤊ 0⤋
This question is really to complicated to answer in full but basically:
DNA is made up of a sugar and phosphate backbone with nucelotide bases. The nucleotide associate with one another on opposite strands forming a ladder like structure. The DNA twists into a helix so that the bases are stacked closely together.
There are a number of other ways DNA can then be packed to save space. For example our DNA is wound around proteins called histones when it is not actively in use so that it can all fit into the nucleus.
2006-09-17 03:21:39 · answer #2 · answered by Ellie 4 · 0⤊ 0⤋
The shape that DNA assumes is a combination of intermolecular forces and intramolecular bonding ; hydrogen bonds between the bases, steric factors , phosphate backbone, etc.
For instance the phosphate backbone is negatively charged , and are situated on the exterior of the surface of the helix to minimize replusion.
Even interaction with the surrounding would affect the shape of DNA. If you change the medium in which the DNA is found in, its shape would alter depending on the medium.
There are also different sub types of DNA configuration; A , B and Z.
Infact some people are playing around with DNA shapes :
http://www.npr.org/templates/story/story.php?storyId=5281562
2006-09-17 05:50:34 · answer #3 · answered by JY leong 1 · 0⤊ 0⤋
it forms a double hilex which turns around itself .. this chemically is due to the attraction forces between the basis of the DNA. physically or the other reason, is to minimize its space as spiral things can be like springs so they can coil to each other and take a less space in the small nucleolus inside the nuclus of a cell
2006-09-17 09:53:06 · answer #4 · answered by Sea Bass 4 · 0⤊ 0⤋
The backbone of DNA is made of phosphates, which are hydrophillic (water loving, polar), while the bases are hydrophobic (non-polar). In order to keep the bases away from water, they need to stack up on themselves. In order to maintain the length of the covalent bonds between phosphates (about 6 Angstroms), the bases need to be set on top of each other on an angle (the bases are 2.7 Angstroms apart otherwise). The bases are stacked up like stairs, then twisted, to keep water away. This forms the double helix that we all know and love.
2006-09-17 16:23:15 · answer #5 · answered by bflute13 4 · 0⤊ 0⤋
The way the chemical bonds connect the two strands and the size of the molecules contained in the strands cause the them to spiral.
2006-09-17 03:17:14 · answer #6 · answered by abakerchick 3 · 0⤊ 0⤋
If they werent in the shape of a double helix, they would take up to much space. It saves space to be twisted together rather than being spread out and straight.
2006-09-17 03:11:34 · answer #7 · answered by Anonymous · 0⤊ 0⤋
To save space.
2006-09-17 04:31:17 · answer #8 · answered by Anonymous · 0⤊ 0⤋
Coz it's not a square?
2006-09-17 02:48:04 · answer #9 · answered by tildypops 3 · 0⤊ 1⤋