The answer–perhaps not surprisingly–is yes. Consider this simple common emitter amplifier (I modeled it in PartSim, if you’d like to open it): While those steps aren’t very complex ...

[Paulo]’s calculator will therefore compute most of the characteristics of two class A common emitter/collector amplifiers for specified loads.

If the collector and emitter are connected to a battery ... which is how a transistor functions as an amplifier. It’s similar to the way you control the flow of water with a faucet.