Answer:
It responses when cell surface receptors are activated especially trans membrane receptors such as taste, smell and vision.
Step-by-step explanation:
GTPases are a large group of hydrolase enzymes that link to the nucleotide guanosime triphosphase and hydrolyze it to guamosine diphosphate.
Signal transduction is the process whereby a chemical or physical signal is transmitted using a cell as series of molecular events or activities mostly protein Phosphorylation catalyzed by protein kinases which are finally resulting in a cellular response. Receptors are seen as proteins which can sense stimuli even though most times, sensors are used.