Gene expression

Cards (32)

  • What does gene expression involve?
    Reading DNA code to produce proteins
  • What are the two major processes involved in gene expression?
    Transcription and translation
  • What is the role of RNA polymerase in transcription?
    It joins RNA nucleotides to form mRNA
  • What type of RNA is produced during transcription?
    Messenger RNA (mRNA)
  • What happens to the DNA during transcription?
    It unwinds and unzips
  • What binds to the exposed complementary bases during transcription?
    Free RNA nucleotides
  • What is formed when RNA nucleotides join together?
    A phosphodiester bond
  • What is produced after transcription is complete?
    Pre-mRNA
  • What must happen to pre-mRNA before it can code for a protein?
    It must undergo splicing
  • What are the non-coding regions in pre-mRNA called?
    Introns
  • What are the coding regions in pre-mRNA called?
    Exons
  • Where does mature mRNA go after splicing?
    It passes out of the nucleus
  • What are codons?
    Groups of 3 bases on mRNA
  • What is the role of tRNA in translation?
    It brings specific amino acids to ribosomes
  • What is the start codon in mRNA?
    AUG
  • What happens when a tRNA anticodon binds to an mRNA codon?
    It brings a specific amino acid
  • What forms between two activated amino acids during translation?
    A peptide bond
  • What happens to the ribosome during translation?
    It moves along the mRNA codons
  • What happens when a stop codon is reached during translation?
    The polypeptide chain is released
  • What are gene mutations?
    Changes in the nucleotide base sequence
  • What can cause gene mutations?
    Spontaneous changes during DNA replication
  • What is a substitution mutation?
    One base is exchanged for another
  • What is a deletion mutation?
    A base is lost from the sequence
  • What is an insertion mutation?
    A base is added to the sequence
  • How do mutations affect protein structure?
    They can alter the amino acid sequence
  • What happens if a mutation introduces a stop codon too early?
    A shorter, non-functional protein is made
  • What are hereditary gene mutations?
    Mutations in gamete DNA
  • How are hereditary mutations passed on?
    They are inherited by the next generation
  • What are acquired mutations?
    Mutations occurring during a person's life
  • What can cause acquired mutations?
    Environmental factors or DNA replication errors
  • Where do acquired mutations occur?
    In somatic cells
  • Why can't acquired mutations be inherited?
    They do not occur in gametes