Complete Exam Guide Subject-wise practice platform
Cell Signalling and Receptor Mechanisms · USMLE Step 1

Intracellular (nuclear) receptors differ from cell-surface receptors primarily because:

  1. They bind only proteins, whereas cell-surface receptors bind small molecules
  2. After ligand binding they enter the nucleus and directly regulate gene transcription
  3. They always trigger immediate cellular changes through rapid ion flux
  4. They lack any functional ligand-binding domain of their own
Show answer and explanation

Correct answer: After ligand binding they enter the nucleus and directly regulate gene transcription

Nuclear receptors bind hydrophobic ligands that diffuse into the cell; upon activation they move to the nucleus and act as transcription regulators — unlike cell-surface receptors that use second messengers or ion flow.

Difficulty: Medium Question 14 of 22

Practice all 22 Cell Signalling and Receptor Mechanisms questions

Keep practicing

More Cell Signalling and Receptor Mechanisms questions