Drawing simple diagrams of the structure of single nucleotides of DNA and RNA
Simple shapes can be used to draw the main building blocks of nucleotides and the DNA double helix
Advanced drawing skills are not required!
Pentagons can represent pentose sugars
Circles can represent phosphates
Often shown as a circle with the letter P inside: ℗
Rectangles can represent bases
Covalent bonds can be shown with solid lines
Hydrogen bonds can be shown with dashed lines
Or with complementary shapes that fit together (see diagrams)
Simple shapes can be used to represent parts of nucleotide molecules
Two nucleotides shown bonded together covalently within a strand
When drawing the base pairing, the opposite strand should be antiparallel to the first. The presence of hydrogen bonding is shown, but the numbers/lengths of bonds is not required
An alternative way to draw a DNA strand is to use complementary shapes for the bases
Simple, hand-drawn shapes will suffice in an exam. Expert tip - a large drawing is always easier for an examiner to read (and award marks for) than a small one!Read the question carefully; examiners often want a whole nucleotide to be identified in your diagram and to ensure your diagram includes all 4 complementary bases.You don't have to remember the number of hydrogen bonds between the bases.Also, remember to draw DNA strands as antiparallel (one upside-down versus the other) but you don't have to be able to draw a helix shape!