What makes up the sides and "rungs" of a DNA Molecule?

Answer 1

First of all to the guy above me, DNA is deoxyribonucleic acid, so it cant be made of itself. Next off, the rungs are made of bases. The bases are Adenine, Guanine, Cytosine, and Thymine. The sides are made up of a sugar molecule and a phosphate. Together the base, sugar, and phosphates make up a nucleotide, which is the subunit of DNA.

Answer 2

DNA is made up of two complimentary chains of nucleic acids. Each of these complimentary strains has two ends, a 5' end and a 3' end. They refer to the number of the carbon on the deoxyribose. Put together, they look like this.
5'------------------3'
3'------------------5'
DNA is synthesized by adding another nucleotide onto the 3' hydroxyl group present on the deoxyribose sugar. The phosphate is off of the 5' end of the deoxyribose sugar. If you look at the free nucleotides that are used to synthesize DNA, you notice the that they have three phosphate groups. In the backbone of the DNA you notice that there is only one phosphate separating each of the nucleotides. That is because during the synthesis of DNA, you produce one water molecule and you also release two of the phosphates for each extra nucleotide that you add.
To answer your question, the sides, or the backbone of the DNA is made up of alternating phosphate and deoxyribose residues.
On the carbon labeled #1 on the deoxyribose sugar, you have the base added to it. These bases form the rungs of the DNA molecule. Adenine, Thymine, Cytosine and Guanine are the four possible bases. There are two different types of bases, purines and pyrimidines. They refer to the basic structure, or backbone if you will, of the bases. Adenine and Guanine are purines while Thymine and Cytosine are both pyrimidines. Pyrimidine and purine basically refer to the backbone of these specific bases. On these "backbones" are different groups such as oxygens, hydrogens and methyl groups which make the bases what they are.
There were experiments done that found that in any given molecule of DNA, the percentage of Cytosine and the percentage of Guanine were the same. Likewise, the percentage of Adenine and the percentage of thymine always matched up. This is because Adenine always compliments Thymine and Cytosine always compliments Guanine. So for each step or "rung" as you put it, you either have a thymine paired up with an adenine or a cytosine paired up with a guanine. A purine always needs to be paired up with a pyrimidine. This is because pyridines are quite a bit smaller than purines. If you had two purines paired up, you would make too wide of a rung. If you had two pyridines paired up, the rung would not be big enough. I do not know if you are familiar with the term "hydrogen bonding". It is hydrogen bonding that allows the bases to pair up as they do. Adenine and Thymine have two hydrogen bonds that connect them, whereas Cytosine and Guanine have three hydrogen bonds between them. This gives special properties to the DNA actually. DNA rich in Guanine and Cytosine will denature at much higher temperatures than will DNA rich in Adenine and Thymine.
DNA is a very elegant molecule. The structure was discovered in 1953 by James Watson and Francis Crick. Rosalind Franklin was a crystallographer who gave the pair an X ray of a crystalized DNA molecule. By examining it, they were able to determine that DNA was in fact a double helix. They were also able to determine the distance between the rungs by examining this x-ray. There are some cases in nature where DNA exists as a single strande, but for the most part it exists as a double stranded molecule.
I strongly suggest that you look at the two links given below. The wikipedia article will probably any other answers that you might have. If you have any more questions, just ask. That's what I'm here for :)
- The Mad Scientist

Answer 3

The rungs are made of Deoxyribonucleic acid which is a five carbon sugar. Attached to the first carbon (C1) is an amino acid. A phosphate group PO4 attaches to the carbon (C3). Attached to the fifth carbon is another phosphate group. The phosphate groups attach to other phosphate groups forming a phosphosugar backbone. On the opposite side, the same thing happens, but upside down, called the anti-parallel. If the C5 carbon is facing up it is called 5', if the C3 is facing down it is called 3'. That is how DNA is named.
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Answer 4

phosphate and sugar molecules makes up the sides of the DNA molecule while adenine, cytosine, guanine, thymine makes up the rungs of a DNA MOLECULE