Mutations and Gene Regulation

• Transcription- inside the nucleus mRNA copies a gene that codes for a protein

• Translation- in the ribosome the mRNA is translated (using tRNA) into amino acid chain

• the polypeptide chain folds creating a protein

​Mutation – change in DNA sequence

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Mutations can be induced by a multitude of environmental factors

• Radiation

• Chemicals

• Infectious Diseases​

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Deletion mutation – one or more nucleotides is removed from a DNA sequence​

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Deletion mutations cause frameshift (the entire amino acid sequence is altered past the deletion)

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**count the #of nucleotides*​

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Insertion mutation – one or more nucleotides is added to a DNA sequence​

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Insertion mutations cause frameshift also (the entire amino acid sequence is altered past the deletion)

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**count the #of nucleotides*​

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Substitution mutation – one or more nucleotides is substituted for different nucleotides in a DNA sequence​

Do not cause frameshift

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Silent mutations: the mutation does not affect the sequence of amino acids

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Write an example of the 3 types of gene mutations

1. Deletion

2. Insertion

3. Substitution​

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​Chromosomal Mutations- a large scale change

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in a specific section of the DNA 🡪

causes a protein to malfunction

causes a different protein to be made

Gene mutation vs. Chromosomal mutation ​

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small, like the single change in a nucleotide/nitrogen base

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large, like an entire chromosome

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​Disadvantages

• Diseases (Sickle Cell)

• Cancer

• Disabilities (Down Syndrome)

Advantageous

• Super taster (TAS2R38)

• ​Unbreakable bones (LRP5)

Neutral

• have no impact​

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