Deoxyribose is a monosaccharide consisting of 5 carbon atoms (pentose), which is formed from ribose when it loses one oxygen atom. The empirical chemical formula of deoxyribose is C 5 H 10 O 4 and, due to the loss of an oxygen atom, it is not consistent with the general formula for monosaccharides (CH 2 O) n , where n is an integer.
Physical and chemical properties
The linear deoxyribose formula can be represented as follows: H- (C = O) - (CH2) - (CHOH) 3 -H. However, it exists in the form of a closed ring of carbon atoms.
Deoxyribose is a colorless solid that is odorless and readily soluble in water. Its molecular weight is 134.13 g / mol, melting point 91 ° C. It is obtained from ribose-5-phosphate due to the action of the corresponding enzymes during the chemical reduction reaction.
The difference between ribose and deoxyribose
As already mentioned and as the name shows, deoxyribose is a chemical compound whose atomic composition differs from that for ribose by just one oxygen atom. As shown in the figure below, deoxyribose does not have an OH hydroxyl group on the second carbon atom.
Deoxyribose is part of the DNA chain (deoxyribonucleic acid), while ribose is part of RNA (ribonucleic acid).
It is interesting to note that the arabinose and ribose monosaccharides are stereoisomers, that is, they differ in spatial arrangement relative to the plane of the OH group ring near the 2nd carbon atom. Deoxy arabinose and deoxyribose are one and the same compound, but the second name is used, since this molecule is obtained from ribose.
Deoxyribose and genetic information
Since deoxyribose is part of the DNA chain, it plays an important biological role. DNA - a source of genetic information, consists of nucleotides, which include deoxyribose. Deoxyribose molecules bind one nucleotide to another in the DNA chain through phosphate groups.
It was established that the absence of the OH hydroxyl group in deoxyribose gives mechanical flexibility to the entire DNA chain in comparison with RNA, which, in turn, allows the DNA molecule to form a double chain and be in a compact form inside the cell nucleus.
In addition, due to the flexibility of the bonds between the nucleotides formed by deoxyribose molecules and phosphate groups, the DNA chain has a significantly longer length than RNA. This fact allows encoding genetic information with high density.