Nature of the genetic code

• What is a codon in genetics?

  Every three bases on a gene
• What does each codon code for?

  A specific amino acid
• What is a single gene essentially composed of?

  A sequence of codons
• What does it mean that codons are non-overlapping?

  Each base is only read once
• What does it mean that codons are degenerate?

  Multiple codons can code for the same amino acid
• How many codons are there in most organisms?

  64 codons
• What are STOP codons?

  They signal the end of a polypeptide chain
• What is the sequence of the START codon?

  AUG
• How many codons encode for the 20 amino acids?

  60 codons
• What does it mean that the genetic code is universal?

  It is the same in almost all living organisms
• How does the non-overlapping nature of the genetic code affect reading?

  Adjacent codons do not overlap
• How does the degenerate nature of the genetic code limit mutations?

  It can reduce the impact of mutations
• What is a gene?

  A sequence of bases on a DNA molecule
• What does a gene control?

  Protein structure and function
• What are the components of a DNA nucleotide?

  • Deoxyribose sugar
  • Phosphate group
  • Nitrogenous base (A, T, C, G)
• What is the relationship between genes and proteins?

  • Genes code for amino acid sequences
  • Amino acids form proteins
  • Proteins determine cell functions