GENE REGULATION Gene regulation The ability of an
GENE REGULATION • Gene regulation: The ability of an organism to control which genes are transcribed in response to the environment.
MUTATION • Mutation: a permanent change that occurs in a cell’s DNA. • Can range from changes in a single base pair (Ex: An A instead of a C) in the coding sequence of DNA to the deletion of large pieces of chromosomes. • http: //www. youtube. com/watch? v=efstlgoynlk
POINT MUTATION • Involve a chemical change in just one base pair. • A point mutation is exchanged for another is called a substitution.
POINT MUTATION • Missense mutation: codes for the wrong amino acid. • Nonsense mutation: change the codon for an amino acid to a stop codon. • Silent mutation: a substitution that does not change the amino acid. • Normal Sentence: THE BIG FAT CAT ATE THE WET RAT • Missense Mutation: THE BIZ FAT CAT ATE THE WET RAT • Nonsense Mutation: THE BIG RAT.
INSERTION MUTATIONS • Insertions are additions of a nucleotide to the DNA sequence. • This changes the multiples of three in the DNA sequence from the point of the insertion.
DELETION MUTATIONS • Deletion mutations remove a nucleotide from the DNA sequence. • This changes the multiples of three in the DNA sequence from the point of the insertion.
INSERTION & DELETION MUTATIONS • Normal Sentence: THE BIG FAT CAT ATE THE WET RAT • INSERTION: THE BIG ZFA TCA TAT ETH EWE TRA • DELETION: THB IGF ATC ATA TET HEW ETR AT • These mutations are called frameshift mutations because they change the “frame” of the amino acid sequence.
DUPLICATION MUTATION • A duplication mutation is the repeat of one or more codons.
DUPLICATION MUTATION • Normal Sentence: THE BIG FAT CAT ATE THE WET RAT • Duplication: THE BIG FAT CAT ATE THE WET RAT
• Original DNA Sequence: T A C C T T G G C G A C T … • m. RNA Sequence: A U G, U G G, A A C, C G C, U G A • Amino Acid Sequence: Met Try Asp Arg Cys Stop
• Mutated DNA Sequence #1 T A C A T C T T G G C G A C T… What’s the m. RNA sequence? A U G, U A G, A A C, C G C, U G A(Circle the change) • What will be the amino acid sequence? Met STOP Asp Arg Cys Stop. . • Will there likely be effects? YES What type of mutation is this? Base substitution of T for C causing a NONSENSE mutation.
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