Vitamin E and Alzheimer's Risk. A second study in the July issue of the Archives of Neurology shows that eating foods rich in vitamin E may help lower risks of developing dementia and Alzheimer's disease.
Ribose and Deoxyribose. The 5-carbon sugars ribose and deoxyribose are important components of nucleotides, and are found in RNA and DNA, respectively. The sugars found in nucleic acids are pentose sugars; a pentose sugar has five carbon atoms. A combination of a base and a sugar is called a nucleoside. Ribose, found in RNA, is a normal sugar, with one oxygen atom attached to each carbon atom. Deoxyribose, found in DNA, is a modified sugar, lacking one oxygen atom (hence the name deoxy).
Deoxyribose, or more precisely 2-deoxyribose, is a monosaccharide with idealized formula Hâ(C=O)â(CH2)â(CHOH)3âH. Its name indicates that it is a deoxy sugar, meaning that it is derived from the sugar ribose by loss of an oxygen atom. Since the pentose sugars arabinose and ribose only differ by the stereochemistry at C2â², 2-deoxyribose and 2-deoxyarabinose are equivalent, although the latter term is rarely used because ribose, not arabinose, is the precursor to deoxyribose.