Which type of receptor leads directly to a change in the distribution of ions on opposite sides of the membrane?

• A. Receptor tyrosine kinase.
• B. G protein-coupled receptor.
• C. Ligand-gated ion channel.
• D. Steroid receptor.
• E. Intracellular receptor.

Answer: (C)

Verified step by step guidance

1. Understand the function of each receptor type: Receptor tyrosine kinases, G protein-coupled receptors, ligand-gated ion channels, steroid receptors, and intracellular receptors.
2. Receptor tyrosine kinases are involved in phosphorylation cascades, not directly in ion distribution.
3. G protein-coupled receptors activate secondary messengers, which can indirectly affect ion channels but do not directly change ion distribution.
4. Ligand-gated ion channels open or close in response to a ligand binding, allowing ions to move across the membrane, directly changing ion distribution.
5. Steroid and intracellular receptors typically influence gene expression and do not directly alter ion distribution across membranes.