All GRE Subject Test: Biochemistry, Cell, and Molecular Biology Resources
Example Question #1 : Help With Hormones
Which of the following hormones will elicit a response in cells by attaching to a membrane bound receptor?
Before answering this question, consider what types of hormones would not attach to a membrane bound receptor. Steroid hormones can simply diffuse through the plasma membrane, so they do not need to attach to a receptor there. Cortisol, testosterone, and estrogen are all steroid hormones. This leaves insulin as the only acceptable answer. In fact, insulin attaches to a receptor tyrosine kinase on the outside of cells.