2006-09-02 00:12:06 · 7 answers · asked by chandu 1 in Science & Mathematics ➔ Biology
ACID
DNA - DeoxyriboNucleic Acid
2006-09-02 00:14:35 · answer #1 · answered by Anonymous · 0⤊ 0⤋
It has been found that DNA double helix can exist in three different forms. they are known as:
A DNA
B DNA
Z DNA
The difference between the three different DNA forms are its geometry. In the 'a DNA' the angle between two successive bases on a strand is 32.7# degrees, whereas for the 'b DNA' the angle is 36 degree. In the 'b DNA' the plane containing the base and its complement is parallel to other planes containing a base pair. Whereas in the 'a DNA' this does not hold. The information on the 'z DNA' is not available, but recent research suggests that DNA exists in this form when it is actively being transcribed Into mRNA's. This result is not too surprising since 'z DNA' is a metastable configuration for DNA.
2006-09-02 07:59:31 · answer #2 · answered by Ashish B 4 · 1⤊ 0⤋
Its representation of various forms of DNA
A-DNA and B-DNA are forms of DNA in which the double helix winds to the right. These are 2 different patterns, just named A and B. A and B does not stand for anything.
Z-DNA is a form of DNA in which the double helix winds to the left in a zig-zag pattern. Since its in opposite direction, its named from last that is "Z". Even this doesn't stand for anything
2006-09-02 17:40:07 · answer #3 · answered by akbshetty 1 · 0⤊ 0⤋
There are diff types of Dna.A,B,C,Zforms of Dna. A,B and C forms are right handed and Z is left handed . A has 11base pairs per turn,B has 10.4base pairs and Z contains 12 base pairs per turn.B form is the common one found by watson and crick.when B is dehydrated A form appears.A is broader ,B is intermediate and Z is narrow. and zigzag..helix diameter :A is 25.5A ,B is 23.7A,C is 18.4A....... But A is A-Dna ,B and Z in B and Zforms are used to represent these forms but they do not have any specific reason......
2006-09-02 07:46:38 · answer #4 · answered by vedala 2 · 1⤊ 0⤋
They all represent different helix structures of DNA. The Z might stand for zig-zag, because of the shape of the helix structure. As for A and B, they don't stand for anything. They're just used to distinguish the two, like "exhibit A" or "slide tab A into slot B."
2006-09-02 07:21:18 · answer #5 · answered by DavidK93 7 · 0⤊ 0⤋
The DNA helix can assume one of three slightly different geometries, of which the "B" form described by James D. Watson and Francis Crick is believed to predominate in cells.
The A and B forms differ mainly in their sugar pucker. In the A form, the C3' configuration is above the sugar ring, whilst the C2' configuration is below it. Thus, the A form is described as "C3'-endo." Likewise, in the B form, the C2' configuration is above the sugar ring, whilst C3' is below; this is called "C2'-endo."
Examples of two other known double-helical forms of DNA, which differ in their geometry and dimensions, are called A- and Z-DNA.
Z-DNA is a left-handed helical form of DNA in which the double helix winds to the left in a zig-zag pattern (instead of to the right, like the more common B-DNA form).
2006-09-02 07:18:30 · answer #6 · answered by Country Boy 5 · 1⤊ 0⤋
no its just the name given to the dna they dont stand for anything they r different kind of dna
2006-09-02 07:55:03 · answer #7 · answered by jumping genes21 2 · 0⤊ 0⤋