DNA is called deoxy because the sugar molecule in its backbone, deoxyribose, lacks an oxygen atom at the 2' carbon position. This absence of oxygen distinguishes it from ribose, the sugar found in RNA.
The prefix "deoxy" signifies this missing oxygen, hence the name deoxyribonucleic acid (DNA). The presence or absence of this oxygen atom is a key difference between DNA and RNA, impacting their structures and functions.
In summary:
- DNA's sugar, deoxyribose, lacks an oxygen at the 2' carbon position.
- The "deoxy" prefix in DNA reflects this missing oxygen.
