Cells that respond to peptide hormones usually do so through a sequence of biochemical reactions involving receptor and kinase activation. In order for cells to respond, it is necessary for first and second messengers to communicate. This is possible because ________.
A) hormones alter cellular operations through direct stimulation of a gene
B) peptide hormones are converted by cell membranes enzymes into second messengers
C) G protein acts as the link between first and second messengers
D) the hormone receptor complex moves into the cytoplasm as a unit

Cells that respond to peptide hormones usually do so through a sequence of biochemical reactions involving receptor and kinase activation. In order for cells to respond, it is necessary for first and second messengers to communicate. This is possible because C) G protein acts as the link between first and second messengers .

Explanation:

When the first messengers join the receptor, in the external membrane of the cell, it produces a change in the shape of the receptor that causes the join of the G protein to this structure. The G protein joined to the receptor and the first messenger modulates the activity of the second messengers inside the cell.