RNAProtein160-page18 - instructions cannot be read...

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Gene Expression – DNA to Protein - 18 For example, the DNA for Hemoglobin normally codes for glutamic acid as the #6 amino acid. One hemoglobin mutation codes for valine in this position. The difference is Normal DNA code = CTC or CTT and Abnormal code = CAC or CAA. The result of this base substitution is the genetic disorder sickle cell anemia. Insertions (Duplications) If a new base pair is added to the DNA sequence being replicated, an insertion has occurred. The DNA instructions are now altered, and will be misread. Deletions In a deletion, a base pair is left out during DNA replication, and the DNA
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Unformatted text preview: instructions cannot be read correctly. Insertions and deletions will affect the reading of the entire gene past the point of change. (In theory, if an insertion or deletion involved complete triplet nucleotides, there would be just one amino acid affected, and the remaining codes could be read as usual.) In contrast, a base substitution may affect only a short sequence (one nucleotide triplet) of the DNA reading. Inversions and translocations can also involve just a few nucleotides....
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