We do not have anything hard this week. Still, we need to keep our mind sharp, and learn some new stuff.
Searching in electronic spreadsheets
I’ve shared with you a Google Sheet for this homework. There are two issues that we want to solve.
In the first worksheet (called Hamming) you can see the code we saw in the last class to calculate the Hamming distance between genetic codes. But it was too complicated to copy-and-paste each genetic code sequence. Instead, we want to tell the computer to do it for us.
You can see that there is a place to write the id of
the genetic code. This can be used to search in the second worksheet,
called codes, and fill automatically the
sequence. The best way to do this is to use the
MATCH() to find the row name corresponding to the
genetic code, and then use the function
INDEX() to get the
genetic code located in the row previously identified.
Your homework is to learn how to use the
INDEX() functions in Excel or Google Sheet. Be aware that
the names may change if you use Turkish or any other non-English
language as your default language
Reading BLOSUM62 substitution scoring matrix
In the last worksheet we have the BLOSUM62 matrix. We want to
automatically find the score for the two amino acids written in
row and column, in
D29. This can also be solved using
When we spoke about “the number of comparisons” someone suggested that the number was 25! (twenty five factorial). That was not the correct answer, but was in the correct direction.
How much is 25 factorial? If you can count one number in one second, how long would it take to count until 25 factorial?
Give your answer in reasonable units. Approximate answers are accepted, as long as they are not too far away from the final result.