객관식
Which of the following is an example of an ion-channel receptor?
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14. Cell Signaling
Overview of Cell Surface Receptors
객관식
Which of the following best describes the primary function of cell surface receptors in cell signaling?
A
They degrade signaling molecules to terminate the signal.
B
They synthesize signaling molecules for export from the cell.
C
They transport ions directly across the plasma membrane.
D
They bind extracellular signaling molecules and initiate a cellular response.
검증된 단계별 안내1
Understand the role of cell surface receptors in cell signaling: Cell surface receptors are specialized proteins located on the plasma membrane that detect and respond to extracellular signaling molecules (ligands). These receptors play a critical role in communication between cells and their environment.
Eliminate incorrect options by analyzing their functions: (1) Degrading signaling molecules is not the primary function of cell surface receptors; this is typically performed by enzymes. (2) Synthesizing signaling molecules is a function of other cellular machinery, such as enzymes or organelles like the endoplasmic reticulum. (3) Transporting ions directly across the plasma membrane is a function of ion channels or transporters, not cell surface receptors.
Focus on the correct function: Cell surface receptors bind to specific extracellular signaling molecules (e.g., hormones, neurotransmitters, or growth factors) and initiate a cascade of intracellular events that lead to a cellular response. This process is known as signal transduction.
Relate the correct function to the answer choices: The correct answer aligns with the description of cell surface receptors binding extracellular signaling molecules and initiating a cellular response, which is their primary role in cell signaling.
Conclude that the correct answer is: 'They bind extracellular signaling molecules and initiate a cellular response,' as this best describes the primary function of cell surface receptors in cell signaling.
