python - checking if the first letter of a word is a vowel

Before I ask the question I want to let you know that I am not an experienced programmer but someone learning the basics of python on codecademy.com.

I am trying to use python to write a function that checks whether the first letter of a given word, for instance "ball" is a vowel in either uppercase or lowercase. So for instance:

#here is a variable containing a word:
my_word = "Acrobat"

#letters in vowel as a list
the_vowel = ["a","e","i","o","u"]

How do a check that the first letter in "Acrobat" is one of the vowels in the list? I also need to take into consideration whether it is upper or lowercase?