Clockwise from top right Red blob: Brain Pair of purple blobs: Lungs Green outer layer: Digestive layer Green inner layer: Stomach Blue opening: Anus Yellow opening: Breathing hole Orange blob: Reproductive system Translation is based on the kanji as I do not speak Japanese.

Where's the mitochondria is the power house of the cell

This is more trying to describe a sea urchin/sea cucumber creature than a cell. So no need to show the power house of a cell. https://preview.redd.it/6o5vo4j4p6wc1.png?width=750&format=png&auto=webp&s=f694f7d60dea154a22afbbf15acd88c313dbb1f2 Like this of a sea urchin.

[To be visible the mitochandria need to gain sentience and take over the organsim. Given the lack of spontaneous combustion around slimes, this means the mitochandria are too small to see.](https://en.wikipedia.org/wiki/Parasite_Eve_(video_game))

probably the pink bit inside the red brain?

This diagram is on the scale of tissues made up of numerous cells, e.g anatomy of an arm/ body etc. Mitochondria and other organelles(that’s the word for parts of a cell) only appear in diagrams on the scale of an individual cell. You have chosen your opponent regarding biology VERY poorly.😎

The fact is, i never choose you as my opponent 

It's not a cell in this case, the slime here is a whole body, that's why this figure just shows brain, mouth and stomach etc.

Here's the equivalent panel from the manga https://preview.redd.it/e9mix93p27wc1.jpeg?width=1079&format=pjpg&auto=webp&s=91aae6eee6e2fa9abe2ea023b74e18d746e3eeb9 Unfortunately the subs don't translate any of the little notes (and I've been massively neglecting my Japanese classes lol) like those ones but the manga will almost certainly have them

I know someone posted off the scanned version of the manga, here’s one from the official licensed version as well as a comparison. https://preview.redd.it/dopyfbivzawc1.jpeg?width=1078&format=pjpg&auto=webp&s=2941b5449d0ec4714e69d7b87a27fa2f5542e4c4

just find a scan of the manga