The genetic code

• What is the defintion of a triplet?


  A sequence of three DNA bases,codes for a specific amino acid
• What are introns?

  Sections of DNA that do not code
• Where are introns found?

  In eukaryotic DNA, not prokaryotic DNA
• What happens to introns during mRNA processing?

  They are removed and spliced out
• What are exons?

  Sections of DNA that code for amino acids
• What is the definition of the genome?

  Complete set of gene in one cell
• What is the definition of the proteome?

  Full range of proteins in one cell
• How does the genome change over time?

  The genome should never change
• How does the proteome change over time?

  It constantly changes based on proteins
• How many DNA base pairs do humans contain?

  Approximately 3 billion DNA base pairs
• What are the three features of the genetic code?

  1. Degenerate
  2. Universal
  3. Non-overlapping
• What is a start codon?

  First codon that initiates translation
• What is a stop codon?

  Codon that marks the end of translation
• What does it mean that the genetic code is degenerate?

  Multiple triplets code for the same amino acid
• Why is three bases needed to code for amino acids?

  It allows for 64 combinations for 20 amino acids
• What is a silent mutation?

  A mutation that does not affect the amino acid
• Why is the genetic code described as universal?

  Same triplet codes for the same amino acid in all organisms
• What does it mean that the genetic code is non-overlapping?

  Each base is part of only one triplet
• What is the advantage of a non-overlapping genetic code?

  Minimizes impact of mutations on proteins
• How does a point mutation affect a non-overlapping genetic code?

  It affects only one codon/triplet
• What is the impact of overlapping codons on protein structure?

  It can affect multiple amino acids
• Define the term exon ?

  Triplet sequence coding for polypeptide.