Symbolic Interactionism is for sure micro. As far as social constructionism, its a gray area, that's why you're finding two different answers.
SI: Small people. Micro interactions. Think of the interaction between you and a peer. Do you high five or give a thumbs up? Because those are random symbols, but you attribute meaning to them.
Social constructionism is more about the idea of creation. If I created a smartphone App with my beliefs (religious, political, social, moral, ethical), and that app got produced, it is embedded with MY social ideas and beliefs that I CONSTRUCTED and put into this app. Think of the construction aspect as building something and embedding you and your small group's thoughts and beliefs into.
Do you have a specific MCAT question regarding the two of them? If so, post that here and people will take a crack at it.
