nucleotides

• nucleotide is made from a pentose sugar, nitrogenous base, and a phosphate group
• pentose sugars are ribose or deoxyribose
• nitrogenous bases are adenine and guanine (purines) or cytosine, thymine and uracil (pyrimidines)
• pentose sugar in DNA is called deoxyribose
• four possible bases of DNA - adenine, thymine, guanine or cytosine
• pentose sugar in RNA is ribose
• four possible bases in RNA - adenine, uracil, cytosine, guanine