I would like to ask how BLOSUM matrix is constructed and calculated ? I read the wikipedia and I still do not understand it. I do not understand the mathematical calculations as I have low knowledge about logarithms.
Maybe could someone give a simple example and then a real-scenario example of how the BLOSUM matrix can be used and calculated, maybe in relation to the Blast algorithm where it uses the BLOSUM scoring matrix to determine high scoring words for each word in the query sequence ?
Also, why are they different types of BLOSUM matrices like BLOSUM62 and so on ?