Concept explainers
(a)
To determine: The prediction that can be made about impaired protein synthesis after the introduction of a missense mutation in the mtAlaRS gene.
Introduction: Infantile cardiomyopathy is a fetal disorder during the first year of life due to the defects in the function of heart muscles. The heart muscles undergo dysfunction due to defects in the function of mitochondria.
(b)
To determine: The reason behind the type of mutation that results in more harmful dysfunction in the translation in mitochondria.
Introduction: The mutation in mitochondrial alanyl-tRNA synthetase is caused by two specific changes in the amino acid. The first change occurs at position 155 from leucine to arginine. The second change occurs at position 592 from arginine to tryptophan.
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Concepts of Genetics (12th Edition)
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- Most of the mutations that Yanofsky recovered were missense mutations. However, Yanofsky also recovered a nonsense mutation that changed amino acid number 15 into a stop codon. This codon normally encodes Lysine. Does the recovery of this mutation support the hypothesis that this Lysine residue is critical in the function of the tryptophan synthetase protein? Why or why not?arrow_forwardMetabolic syndrome is a genetic disorder with symptoms of hypertension, elevated blood cholesterol concentrations, and lower-than-normal blood magnesium concentrations. This syndrome is caused by a mutation in mitochondrial DNA (mtDNA) in which a thymine nucleotide is replaced by a cytosine nucleotide. Which of the following identifies the mutated mtDNA and the corresponding mRNA and tRNA produced in a person with metabolic syndrome if the normal mtDNA triplet is TCG? Select one: a. Mutated mtDNA: CCG mRNA: GGC tRNA: GGC b. Mutated mtDNA: TCG mRNA: UGC tRNA: ACG c. Mutated mtDNA: CCG mRNA: GGC tRNA: CCG d. Mutated mtDNA: TTG mRNA: AAC tRNA: UUCarrow_forwardAs stated in the text, adenosine deaminase deficiency can be treated by injection of the stabilized enzyme. Why might this treatment be effective, while injection of the missing enzyme is ineffective in other conditions, such as HGPRT deficiency or a deficiency of one of the mitochondrial deoxyribo- nucleoside kinases?arrow_forward
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