2.4.2 Effects on Protein Function

• A genetic mutation is a change in the DNA
• What is a genetic mutation?

  Change in DNA sequence
• Point mutations involve the addition or deletion of bases in DNA.

  False
• Order the types of point mutations from least to most severe effect on protein structure.

  1️⃣ Silent mutation

  2️⃣ Missense mutation

  3️⃣ Nonsense mutation
• Match the type of point mutation with its effect on protein structure.

  Silent mutation ↔️ No change in protein structure

  Missense mutation ↔️ Alters protein structure

  Nonsense mutation ↔️ Creates a truncated protein
• What is the effect of frameshift mutations on protein structure?

  Shifts reading frame
• Silent mutations change a codon to another codon for the same amino acid.
• What is the outcome of a missense mutation?

  Altered protein structure
• Frameshift mutations occur due to the addition or deletion
• GGA and GGC both code for glycine.
• What factors can induce genetic mutations?

  External factors
• Silent mutations can change the DNA sequence but not the protein structure.
• Order the steps of how mutations can affect protein structure, from the mutation type to its effect on protein structure.

  1️⃣ Point mutation

  2️⃣ Change in DNA sequence

  3️⃣ Alteration of codon

  4️⃣ Effect on amino acid sequence

  5️⃣ Change in protein folding
• Match the mutation type with its effect on protein structure.

  Nonsense mutation ↔️ Truncated protein

  Frameshift mutation ↔️ Entirely different sequence
• Why do silent mutations have no effect on protein function?

  No change in amino acid
• Mutations can cause proteins to lose their native 3D structure.
• Misfolded proteins can aggregate, preventing normal function
• What happens to altered protein structures that become unstable?

  Degrade quickly
• A GGA codon and a GGC codon both code for the amino acid glycine
• A missense mutation replaces a hydrophobic amino acid with a hydrophilic one.
• A nonsense mutation creates a premature stop codon.
• What determines the interactions and activity of a protein?

  Its structure
• Mutations can cause proteins to lose their native 3D structure, disrupting active site folding.
• Misfolded proteins can aggregate, preventing normal function.
• Altered protein structures may become unstable and degrade quickly.
• What is a genetic mutation?

  Change in DNA sequence
• Order the subtypes of point mutations from least to most severe in terms of protein effect

  1️⃣ Silent mutation

  2️⃣ Missense mutation

  3️⃣ Nonsense mutation
• Match the mutation type with its description:

  Point mutations ↔️ Single base substitution

  Frameshift mutations ↔️ Addition or deletion of bases
• A silent mutation results in no change in the amino acid sequence.
• What does a missense mutation alter in a protein?

  Amino acid sequence
• A frameshift mutation leads to an entirely different amino acid sequence.
• Match the mutation type with its effect on protein structure:

  Silent mutation ↔️ No change

  Missense mutation ↔️ Alters amino acid sequence

  Nonsense mutation ↔️ Creates stop codon

  Frameshift mutation ↔️ Shifts reading frame
• A silent mutation has no effect on protein structure.
• A missense mutation can alter the amino acid sequence.
• What is the result of a nonsense mutation on a protein?

  Truncated protein
• A frameshift mutation shifts the reading frame, leading to an entirely different amino acid sequence.
• What is a genetic mutation?

  Change in DNA sequence
• Point mutations are single base substitutions
• Frameshift mutations involve the insertion or deletion of bases in DNA.
• Match the mutation type with its effect on protein structure:

  Silent mutation ↔️ No change

  Missense mutation ↔️ Alters amino acid sequence

  Nonsense mutation ↔️ Creates truncated protein

  Frameshift mutation ↔️ Entirely different sequence