What are DNA mutations?

• What is the definition of a mutation?

  A change in the DNA base sequence
• What can cause mutations in DNA?

  Carcinogens and certain types of radiation
• When do mutations commonly occur?

  During DNA duplication before cell division
• How do carcinogens affect mutations?

  They increase the risk of mutations occurring
• What is a gene?

  A section of DNA that codes for protein
• What is a triplet or codon?

  A group of 3 bases in DNA
• What does the codon ACC code for?

  Amino acid 7
• What happens if a mutation changes a codon?

  The amino acid coded by it may change
• How can a mutation affect protein function?

  It can change the protein's shape or function
• What is an enzyme's active site?

  The region where substrates bind
• Why do most mutations have no significant effect?

  They often only slightly affect proteins
• What is non-coding DNA?

  DNA that doesn't code for proteins
• What role does some non-coding DNA play?

  It helps in gene expression regulation
• Why might a nerve cell not produce hemoglobin?

  Hemoglobin is only needed by red blood cells
• What are the three specific types of mutations?

  • Substitutions
  • Insertions
  • Deletions
• What is a substitution mutation?

  One base is changed for another
• How does an insertion mutation affect the DNA sequence?

  An extra base is added, shifting others
• Why are insertion mutations considered worse than substitutions?

  They alter all subsequent codons
• What happens during a deletion mutation?

  One base is removed, shifting others left
• How does a deletion mutation affect the DNA sequence?

  It alters all subsequent codons
• What are the consequences of mutations on proteins?

  • Change in amino acid sequence
  • Altered protein shape or function
  • Potential loss of enzyme activity
  • Most mutations have minimal effects