What is the shape of a dna molecule?

The shape of a DNA molecule is called a double helix, which looks like a twisting ladder. The "rungs" are made from four nitrogenous bases: adenine, thymine, guanine and cytosine. Sugars and phosphate groups are also part of the structure. read more

DNA Structure Image by Madprime via Wikimedia Commons. A closer look at the chemical structure of DNA includes the four nitrogenous bases Adenine (A), Thymine (T), Guanine (G), and Cytosine (C). read more

DNA was known to be a long polymer composed of only four types of subunits, which resemble one another chemically. Early in the 1950s, DNA was first examined by x-ray diffraction analysis, a technique for determining the three-dimensional atomic structure of a molecule (discussed in Chapter 8). read more