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).
DNA is a polymer of nucleotides. Each nucleotide consists of a phosphate group, a molecule of deoxyribose, and one of four bases. Deoxyribose is a pentose sugar (it has five carbon atoms). In DNA the sugar residue includes a five-membered ring comprising four of the carbons and one oxygen atom. The fifth carbon is attached to one of the other carbons. Deoxyribose takes its name from ribose (the sugar in RNA).