BIOLOGY 305 Lecture Notes - Lecture 14: Thymine, Reverse Transcriptase, Photolyase
Document Summary
Understand the details of each of the system so that we can compare and contrast between them. Of all the macromolecules, dna is the one that organisms choose to repair. If there is a mistake in making a protein, that protein is just degraded. Dna is repaired because it is passed on through generations. You don"t consider a change a mutation until the checking mechanisms miss it. First you have to recognize the error in dna before you can fix it. If it is replicated, then the next replication will not know that this is an error. The 3"-5" exonuceluse in pol iii and pol i are the first way that dna is repaired. It"s always the base on the new strand that is replaced. That means that the error never really gets made since dna polymerase catches it before replication is complete. There are chemicals and such that damage dna.
