What do the digits 5 and 3 followed by the acute accent signify?
Answer Dear Ashley, The notations, 5′ & 3′, are abbreviations for the terms, 5 prime & 3 prime. They refer to the positions on the deoxyribosyl sugar portions of each nucleotide that forms the phosphodiester linkages in polymeric DNA. The following Figure 4.1 in “Biochemistry of Nucleic Acids” lecture notes on Nucleic Acid Structure ( http://oregonstate.edu/instruction/bb492/lectures/StructureI.html ) from Oregon St. Univ. illustrates this convention, referred to as the “polarity” of the nucleic acid polymer: http://oregonstate.edu/instruction/bb492/fignumbers/Fig4-1.html The deoxyribosyl carbons are numbered in a clockwise direction by these diagrams, starting with that where the base is attached as 1′. Although the phosphodiester bond itself actually links the 3′ with the 5′ carbons in the direction indicated, the 5′ 3′ polarity convention refers to the free carbons on either end of the DNA molecule. “The ‘e’ between the digits” is probably the result of an error in font interpretati
