Deoxyribose is a five carbon monosaccharide, which means that it is a simple sugar that is used to form larger, more complex molecules. This molecule is made up of a pentagon-shaped assembly of carbon atoms. It is ring-shaped and composed of five carbon atoms, ten hydrogen atoms and four oxygen atoms. The assembly of this molecule is similar to other monosaccharides, such as ribose, glucose and fructose.
Deoxyribose and ribose are both five-carbon sugars, yet they differ from each other in one very specific way. In ribose, a hydroxyl (hydrogen-oxygen) molecule is attached to three of the carbon molecules, but in deoxyribose, one of the carbons in the deoxy ring is missing an oxygen atom and has only a hydrogen atom attached to it instead. In fact, deoxyribose is derived by removing the oxygen from the ribose molecule. This missing oxygen is the differentiating factor between these two sugars and the prefix "de" implies a negative, or that a ribose molecule is less one oxygen molecule.
Deoxyribose is found in the cells of all living organisms, as it is a key component of deoxyribonucleic acid (DNA). DNA is made up of two chains of nucleotides bonded together. A nucleotide is formed when a 5-carbon sugar bonds to a phosphate group and a nitrogen-containing base. Nucleotides can have either a deoxyribose or ribose sugar as the 5-carbon sugar, and depending on which sugar is used, the nucleic acid that is formed will be either DNA or ribonucleic acid (RNA).
When a nucleotide is formed, an organic base, such as adenine, thymine, guanine or cytosine, bonds to the first carbon of the pentagon shape of the deoxyribose, while the phosphate group is bonded to the fifth carbon. The nucleotides then bond together between the third and fifth carbons of the deoxyribose molecules. This method of bonding creates a nucleotide chain that has the bases all on the same side of the chain.
When DNA forms its double-helix structure, bonds are formed between complementary bases of two chains of nucleotides. The adenine and thymine join together through two hydrogen bonds and guanine and cytosine pair through three hydrogen bonds. It is thought that the fact that the hydroxyl molecule was replaced by a hydrogen atom is what gives deoxyribose the right shape to allow the structure of DNA molecules to form. This gives the helix strength as well as flexibility to compact the important information into the small area of the cell. The code that is formed due to the bonding of the nucleotides to make up the nucleic acid chain is what provides the genetic information to the cell.