MEDRADSC 2X03 Chapter Notes - Chapter 2: Brca1, Replication Protein A, Western Blot
8 Jul 2016
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Document Summary
Molecular mechanisms of dna and chromosome damage and. There is strong evidence that dna is the principal target for the biologic effects of radiation, including cell killing, carcinogenesis, and mutation. A consideration of the biologic effects of radiation, therefore, begins logically with a description of the breaks in dna caused by charged- particle tracks and by the chemical species produced. Deoxyribonucleic acid (dna) is a large molecule with a well-known double helical structure. It consists of two strands held together by hydrogen bonds between the bases. The backbone of each strand consists of alternating sugar and phosphate groups. Attached to this backbone are four bases, the sequence of which specifies the genetic code. Two of the bases are single-ring groups (pyrimidines); these are thymine and cytosine. Two of the bases are double-ring groups (purines); these are adenine and guanine. The structure of a single strand of dna is illustrated in figure 2. 1.
