If you could give an example from a scientific source, that would be helpful.
The specific phrase "mitochondria is the powerhouse of the cell" or “the mitochondria is the powerhouse of the cell" appears to be a meme. Memes can proliferate even when they aren’t grammatical or well worded; it’s not exactly the same thing as “popular usage” of an ...
"There" indicates the location of the missing functional system.
Adverbs can indicate the place of the action of the verb.
Accordingly, "there" is an adverb modifying the verb "appear."
The sentence has an un-necessary plural form of "system."
It is (logically) more concise to say "no system" (as in not even ...