a. Load into R dataset aaMap (available in Biobase), determine and describe data type of each column.

b. Store, remove and recover it using save and load functions (use the help command ? and read documentation), demonstrate its removal and recovery, using ls function.

c. Save it in a file using write.table function

d. Open the file using text editor, add a column describing amino acid side chain charge at pH=7 (you can use http://en.wikipedia.org/wiki/Amino_acid in order to get neutral/positive/negative charge annotations, or you can even come up with some random numbers, this exercise is about modifying the data and loading them back, not about amino acids), save file, import it back into R, demonstrate that column was added to the data frame