difference between dideoxyribose and deoxyribose
Dideoxyribose is a modified sugar that lacks a hydroxyl (-OH) group on its 3' carbon. This is important in DNA sequencing because when a nucleotide containing dideoxyribose is incorporated into a growing DNA chain, it cannot form a phosphodiester bond with the next nucleotide, which terminates chain elongation.
Deoxyribose is a sugar found in DNA that has a hydroxyl (-OH) group on its 3' carbon, which allows for continued chain elongation during DNA synthesis. It is similar to ribose, the sugar found in RNA, but lacks an additional hydroxyl group on its 2' carbon.
Dideoxyribose and deoxyribose are both types of sugars found in DNA molecules, but they differ in their structure and function. Here's the difference between the two:
1. Structure:
- Dideoxyribose: Dideoxyribose is a modified form of the sugar ribose. It lacks a hydroxyl (-OH) group on the 3' carbon atom, as well as the 2' hydroxyl group found in ribose and deoxyribose.
- Deoxyribose: Deoxyribose is a sugar that is derived from ribose by the removal of an oxygen atom. It contains all the hydroxyl (-OH) groups except for the 2' hydroxyl group.
2. Role in DNA sequencing:
- Dideoxyribose: Dideoxyribose is commonly used in DNA sequencing techniques, particularly in the Sanger sequencing method. It acts as a chain-terminating nucleotide, preventing further DNA chain elongation when it is incorporated into the DNA chain by DNA polymerase.
- Deoxyribose: Deoxyribose is the regular sugar component of DNA. It forms the backbone of DNA alongside phosphate groups. The hydroxyl groups on deoxyribose provide sites for connecting the phosphate groups and the nitrogenous bases, forming the DNA double helix structure.
In summary, dideoxyribose is a modified form of ribose that lacks certain hydroxyl groups, and it is used as a tool in DNA sequencing. Deoxyribose, on the other hand, is the regular sugar found in DNA and is essential for building the DNA molecule.