2.4.2 Effects on Protein Function

• What is a genetic mutation?

  Change in DNA sequence
• A genetic mutation is a change in the DNA
• Point mutations involve single base substitutions in DNA.
• What is a frameshift mutation?

  Addition or deletion of bases
• A silent mutation changes a codon but codes for the same amino
• A missense mutation always results in a non-functional protein.

  False
• What does a nonsense mutation create in a protein sequence?

  Stop codon
• Match the mutation type with its effect on protein:

  Silent mutation ↔️ No change in protein

  Missense mutation ↔️ Alters protein structure

  Nonsense mutation ↔️ Truncated protein

  Frameshift mutation ↔️ Shifts reading frame
• Give an example of a silent mutation.

  $GGA - > GGC$
• A missense mutation changes a codon to one that codes for a different amino
• A nonsense mutation always leads to a non-functional protein.
• Order the following mutation types based on their effect on protein structure, from least to most severe:

  1️⃣ Silent mutation

  2️⃣ Missense mutation

  3️⃣ Nonsense mutation

  4️⃣ Frameshift mutation
• What is the term for a misfolded protein that aggregates with others?

  Aggregation
• Mutations can cause proteins to lose their native 3D structure.
• Altered protein structures may become unstable and degrade due to their stability
• What are the two main causes of genetic mutations?

  Spontaneous or external factors
• What is the definition of a genetic mutation?

  Change in DNA sequence
• Genetic mutations can be caused by spontaneous or external factors
• Mutations can affect protein structure and function.
• What is a genetic mutation?

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

  Silent mutation ↔️ Protein remains unchanged

  Missense mutation ↔️ Alters amino acid sequence

  Nonsense mutation ↔️ Results in a stop codon
• What is the effect of a silent mutation on a protein?

  No change
• A nonsense mutation changes a codon to a stop
• Frameshift mutations shift the reading frame and alter all subsequent amino acids.
• How do genetic mutations affect protein structure?

  Alters amino acid sequence
• Arrange the following steps to describe how mutations affect protein structure:

  1️⃣ Point mutations can be silent, missense, or nonsense

  2️⃣ Frameshift mutations shift the reading frame

  3️⃣ Altered amino acid sequence affects folding

  4️⃣ Modified protein structure changes function
• Point mutations can be silent, missense, or nonsense
• A silent mutation has no effect on protein structure.
• Match the mutation type with its effect on protein structure:

  Silent mutation ↔️ No change

  Missense mutation ↔️ Alters amino acid sequence

  Nonsense mutation ↔️ Truncated protein

  Frameshift mutation ↔️ Entirely different sequence
• What happens if a missense mutation replaces a hydrophobic amino acid with a hydrophilic one?

  Destabilizes hydrophobic core
• Altered protein structure can lead to loss of native conformation
• Misfolded proteins can aggregate and prevent normal function.
• What type of mutation causes sickle cell anemia?

  Missense mutation
• A deletion mutation in the CFTR gene leads to cystic fibrosis
• Match the disease with the affected protein or mutation type:

  Osteogenesis imperfecta ↔️ Mutation in collagen genes

  Cystic fibrosis ↔️ Deletion mutation in CFTR

  Sickle cell anemia ↔️ Missense mutation in HBB
• What type of mutation causes Sickle Cell Anemia?

  Missense mutation
• In Sickle Cell Anemia, glutamic acid is changed to valine
• Which gene is affected by a deletion mutation in Cystic Fibrosis?

  CFTR