After the enzymes amylase breaks down a starch molecule, it can

      Generally speaking, enzymes (which amylase happens to be) do not undergo any permanent structural change while carrying out their function. Some do exhibit transient conformational change during a reaction, but upon completion regain their original form.  

So your initial assumption is correct: once amylase has finished catalyzing the breakdown of starch into less complex sugar molecules, it moves on and repeats the process over and over.

i'm pretty sure it's spores

you didn't give any options but heres what i can tell you: an inference is likely to change based on additional observations. the latter is something that you have seen or sensed using your sensory organs while the former is like a conclusion out from what you have observed.