Concept 6 Review


DNA, made by polymerizing deoxyribonucleotides, forms a double-stranded molecule used for information storage.

Each strand of DNA consists of a "backbone" of alternating units of phosphate and deoxyribose. Purine or pyrimidine bases are attached to the 5-C deoxyribose sugar, and form base pairs with purine or pyrimidine bases from the opposite strand. The only effective pairs are adenine with thymine (A-T pairs) and guanine with cytosine (G-C pairs).