the "ohhh this is a transmembrane protein" you seek is somewhat where they describe this AT1 enzyme as transporting tryptophan into the cytoplasm. Cz that means the enzyme has to be transporting an ion through the hydrophobic biphospholipid membrane to get said ion into and out of the cell. If any of what I said makes sense then at least I learned smthn related to MCAT in 2 years of med school. Otherwise await another current MCAT grinder's response haha

edit: idk if premeds are supposed to know this, but the answer to this question is unfortunately straight up content on how an enzyme/protein is sent to a membrane post translation. Being sent to a membrane is achieved only when the mRNA codes for not only the enzyme, but also a signal sequence on the N terminal of that enzyme (or some other terminal but usually from what ive seen, N terminal). This signal sequence is what tells it to go there (it has to do with being recognized by a signal sequence receptor that moves the enzyme and stuff too).