Add character to specific letter when using "for letter in word"

Question

prefixes = 'JKLMNOPQ'

suffix = 'ack'

for letter in prefixes:
if letter == 'Q':
print(letter + 'u' + suffix)
elif letter == 'O':
print(letter + 'u' + suffix)

else:
print(letter + suffix)

This works to print the correct names
As all names are the letter in prefix followed by ack
eg. Nack, Lack, Jack
However, 2 names need a 'u'. Quack & Ouack
Instead of doing an if and elif,
Why cant I do
if letter == 'Q' or 'O':
When I try this, it adds 'u' to all prefixes... which is incorrect but logically it seems I should be able to do an OR statement

Answer 1

prefixes='JKLMNOPQ'

suffix='ack'

for letter in prefixes:

if letter== 'O' or letter =='Q':
print (letter+'u'+suffix)

else:
print (letter+suffix)

Answer 2

write
if letter == 'Q' or letter == 'O':

Answer 3

Thanks Legends!