(Definition of âcentralâ from the Cambridge Business English Dictionary Â© Cambridge University Press)
Other combinations of the atoms form the four bases: thymine (T), adenine (A), cytosine (C), and guanine (G). These bases are the rungs of the DNA ladder. (It takes two bases to form a rung -- one for each side of the ladder.). A sugar molecule, a base, and a phosphate molecule group together to make up a nucleotide.Nucleotides are abundant in the cell's nucleus. Nucleotides are the units which, when linked sugar to phosphate, make up one side of a DNA ladder.ther combinations of the atoms form the four bases: thymine (T), adenine (A), cytosine (C), and guanine (G). These bases are the rungs of the DNA ladder. (It takes two bases to form a rung -- one for each side of the ladder.). A sugar molecule, a base, and a phosphate molecule group together to make up a nucleotide.
Figure 1: The chemical structure of a nucleotide. A single nucleotide is made up of three components: a nitrogen-containing base, a five-carbon sugar, and a phosphate group. The nitrogenous base is either a purine or a pyrimidine. The five-carbon sugar is either a ribose (in RNA) or a deoxyribose (in DNA) . Â© 2013 Nature Education All rights reserved.