A ligand binds to a transmembrane protein.This causes a conformational change in the protein that is detected by an intracellular protein.The intracellular protein is an enzyme that adds phosphate groups to target proteins.The phosphorylated proteins cause a physiological change within the cell.This is an example of
A) a metabolic pathway.
B) homeostasis.
C) a signal transduction pathway.
D) an allosteric inhibition pathway.

Question

Quizplus · Accepted Answer

The sequence of events described is a classic example of a signal transduction pathway, in which an extracellular signal (the ligand) interacts with a receptor (the transmembrane protein), which in turn triggers a series of intracellular signaling events leading to a physiological response. Option A (metabolic pathway) would involve a series of biochemical reactions rather than a signaling chain. Option B (homeostasis) refers more to the maintenance of stable internal conditions within an organism, and is not directly related to signal transduction. Option D (allosteric inhibition pathway) is a mechanism of regulating enzyme activity, but not directly related to the sequence of events described in this question.

A Ligand Binds to a Transmembrane Protein