The little circular icons represent compounds, hovering over them with the mouse shows their name.
The switches to the left of the organelle icons allow you to completely toggle a process. (photosynthesis is turned off)
There is some stuff missing still, like the ability to more specifically toggle multiple organelles (say if you want to only turn off one of your mitochondria, like if it’s damaged or something), a thing showing how much compounds a process is currently using and how much per minute and stuff, and probably some stuff that I haven’t thought of/forgot about.
EDIT: Here are all my compound icons again