Calculate the entropy of Turkish alphabet and compare with the entropy of English alphabet with using Matlab?
I'll give you a hint: You need the probability distribution of the alphabet (English and Turkish). For English see the Wikipedia "Letter Frequency" page. Now it's possible to compute the Entropy of this distribution.

Note that this is a rough approximation (and an upper bound) since in practice, the letters of a word (and a sentence) are correlated. So, for example, in English the letter 'q' is always followed by 'u'. Thus, the entropy of a source producing English documents is strictly less than the one you'll get from looking at single letters.