Putting It Together: DNA Structure and Replication


In this section we covered several topics, such as:

  • how the structure of DNA directly relates to its ability to store information and programming for cells
  • how complementary bases directly relate to DNA replication in a semi-conservative manner
  • how changes in DNA sequence are monitored and corrected, or else become mutations in the sequence


Let’s expand just a bit on how the process of personalized medicine works. Within any given genome there will be small differences in the DNA sequence. All humans, for example, are 99.99% identical and only differ by 0.01%. These small differences account for many features in an individual, including how he or she responds to disease treatments. Returning to our earlier examples, screening the genome of a patient prior to prescribing Warafin for blood clots allows clinicians to determine if the drug will even work and if so, to pinpoint a specific dosage. In the case of colorectal cancer, the KRAS protein can be examined to determine if cetuximab will be effective. This is an important step as this drug is ineffective in about 40% of patients. Similarly anti-breast cancer treatments can be assessed prior to trial-and-error in a patient based on the DNA sequence of key receptors in the body.

Visit this site to learn more about how FDA regulations come into play.