3. What would be the implication for the shape of the DNA molecule if a purine was always matched across the helix with a purine and a pyrimidine with a pyrimidine? Support your answer with course content.
If a purine was always matched with a purine and a pyrimidine with a pyrimidine, the DNA molecule would become more rigid and the overall shape of the helix would be altered. This is because purines are larger molecules than pyrimidines, so pairing them together would create a larger gap between the two strands of the DNA molecule. This could potentially affect the stability and functionality of the DNA molecule. Additionally, the specific pairing of purines with pyrimidines is necessary for the double helix structure of DNA to maintain its stability and function properly. Matching purines with purines and pyrimidines with pyrimidines would disrupt this natural pairing and could have negative implications for the genetic information stored in the DNA molecule.
