Carbohydrates include sugars and their polymers. Monosaccharides have the general formula of (CH2O)n. The number of these units forming a sugar varies from three to seven with hexases, trioses, and pentoses found most commonly. A sugar can be an aldose or a ketose depending on the location of the carbonyl group. Additional diversity is provided by the spatial arrangement of parts around asymmetric carbons. These small structural differences affect the recognition and interaction …showed first 75 words of 755 total…

…showed last 75 words of 755 total…that consists of a pentoses covalently bonded to a phosphate group and a nitrogenous base. There are two families of nitrogenous bases. Pyrimidines, including cytosine and thymine, have six-membered rings of carbon and nitrogen atoms. Purines, adenine and guanine, add a have membered ring to the pyramidine ring. DNA is organized in the shape of a double helix. The double helix is formed by the hydrogen bonding between specific bases (A, T, G and C).