These examples do not show the acids which are providing the protons. Br nsted-Lowry bases. Be sure to note the distinction between ammonia and ammonium . They sound very much the same and their formulas are very similar, but their chemical properties are quite different. They are different because one has one more proton than the other.
Ammonia is a base and ammonium is an acid.
We'll take up another aspect of their relationship when we consider conjugate pairs.