For proper ignition or combustion, 3 things must exist.
A misfire on cylinder 5 only means a misfire. Okay, so you changed the spark plugs and the ignition coil. Great, pretty sure we can rule out the lack of spark. I'd recommend changing the wires as well. Old wires will have higher resistance resulting in the spark plug not producing a good spark.
Now for the fuel part. The injector must operate at injecting fuel into the combustion cycle or there will be a misfire. Injectors seldom fail although they can. Testing injector operation requires a good lab scope because a regular multi-meter simply isn't fast enough.
Try pouring in some injector cleaner into the fuel.
Oxygen. Change your air filter! If you haven't already.
The likely problem if you know there's spark, and oxygen is getting through a clean air filter, is the #5 injector. Its either plugged, or it has actually failed. Only a shop has the diagnostic lab scope needed to test injector operation.
ASE automotive student