Question

A polar molecule such as a protein hormone usually binds to a(n)
Select one:
a. transmembrane protein.
b. protein kinase.
c. ion channel.
d. second messenger.
e. phospholipid.

Vitamin A is a relatively small, lipid-soluble molecule that can behave as a hormone. Based on what you have learned, which of the following would you predict about its receptor?
Select one:
a. It would be a protein kinase receptor.
b. It would be in the cytoplasm.
c. It would be an ion channel receptor.
d. It would involve a G protein.
e. It would not exist; vitamin A would not have a receptor.