What happens to the cell without mitochondria?
Well that depends on what cell it is. A eukarytoic cell (with nucleus) needs mitochondria to fuel basic cellular function. By adding cyanide to the cell ATP can no longer be used by the cell, which would be the best representation of what would happen if we had no mitochondria. I don’t think I need to explain what happen if you took cyanide. (thud…) However prokarytoic cells (no nucleus) lack any complex membrane bound organelles so it produces its energy by aerobic respiration in the cytoplasm. To answer your question the cell would die, other than if it were prokarytoic where it doesn’t have mitochondria anyway.