DNA Paper Model Imagine DNA is a twisted ladder. The outside of the ladder is made up of alternating sugar and phosphate molecules. The sugar is called deoxyribose. The rungs of the ladder are made of a pair of molecules called nitrogen bases. There are four nitrogen bases in DNA: adenine, guanine, cytosine, and thymine. Because of the chemical structures of the bases, adenine only pairs with thymine, and cytosine only pairs with guanine to form a rung.

STEP 1: Each group member should receive one sheet of phosphate molecules and one sheet of deoxyribose molecules. Each group member will receive a different sheet of nitrogen bases. Color the molecules: Deoxyribose = Orange Phosphate = Purple Adenine = Red Thymine = Green Cytosine = Yellow Guanine = Blue Cut out the molecules.

STEP 2: Arrange your molecules to make nucleotides that each include one phosphate molecule, one deoxyribose molecule and one nitrogen base. Using a SMALL piece of tape, attach the nitrogen base molecule to the sugar molecule by matching up the dots. Using a SMALL piece of tape, attach the phosphate molecule to your model by matching up the stars.

A-T-T-C-C-G-T-A-G-C STEP 3: Arrange your nucleotides to create a strand that reads: A-T-T-C-C-G-T-A-G-C Using a SMALL piece of tape, attach the phosphate molecules to the sugar molecules by matching up the squares.

STEP 4: Using a SMALL piece of tape, attach the complimentary nucleotides to the DNA strand you created. Using a SMALL piece of tape, attach the phosphate molecules to the sugar molecules by matching up the squares to complete your DNA strand.

STEP 5: Bring your DNA strand to Mr. ague to join up with other lab group’s models.