p p p p = phosphate .. \ / \ / \ / \ / ... s s s s s = sugar | | | | b b b b b = basewhere each b can be any one of four bases: = adenine, = thymine, = cytosine, = guanine.
p p p p ... 3'\ / \ / \ / \ / \ /5' ... s s s s s | | | | | | | | | | | | | | | s s s s s ... 5'/ \ / \ / \ / \ / \3' ... p p p p |
In what follows,
this schematic representation
of a segment of a DNA molecule
will be abbreviated to: |