Which of the following are characteristics of G protein-coupled receptors?
1) They typically have seven transmembrane domains that are embedded in the cell membrane.
2) They carry hydrophilic portions of protein that extend into the extracellular matrix as well as the cytosol.
3) The receptor region is located on the extracellular portion of the protein.
4) Most work in concert with G proteins.
a. 1, 2, and 4 are characteristics of G protein-coupled receptors.
b. 1, 2, and 3 are characteristics of G protein-coupled receptors.
c. Only 1 and 2 are characteristics of G protein-coupled receptors.
d. All of the listed statements are characteristics of G protein-coupled receptors.
