In which case, it depends on the type of inhibitor. A competitive inhibitor has a structure similar to the substrate, hence would bind to the active site as well, competing with the substrate for the enzyme active sites, decreasing enzymatic activity. A non-competitive inhibitor binds to the allosteric site of the enzyme, causing a structural change in the enzyme active site shape.
There's a difference between the effects of cold-brewed coffee vs. hot-brewed coffee: because different chemical reactions are achieved at higher temperatures, cold-brewed coffee will have a smoother caffeine effect and overall less acidity, which some people experience as part of the kick..
Acid reflux and heartburn can be caused by coffee due to the way it relaxes the lower esophageal sphincter. This small muscle should remain tightly closed once you've eaten to prevent the contents of your stomach from coming back into the esophagus and burning its delicate lining with hydrochloric acid.