BLAST and (Im)probability

Learning outcomes

After working through this module you will be able to:

  • Use the law of combining to count the number of possible combinations of items from one or more sets.
  • Apply the law of combining to deduce the number of nucleotide sequences and amino acid sequences in a given context.
  • Multiply and divide numbers given in scientific notation.
  • Deduce the average number of nucleotide sequences per amino acid sequence.
  • Deduce the likelihood of a particular nucleotide sequence being catalogued in BLAST.

Module contents

1: Combinatorics
2: Combining letters into words
3: Many names for large numbers
4: Four-letter alphabet
5: How many base sequences?
6: How many AA sequences?
7: Division
8: How many ways can you make a protein?
9: To be or not to be... in blast
10: Blast: do try this at home
11: Summary