The functioning of cell surface receptors involves several steps:
1. Ligand Binding: The receptor binds to its specific ligand with high affinity. This interaction is often highly selective.
2. Conformational Change: Ligand binding induces a conformational change in the receptor, which is essential for subsequent steps.
3. Signal Transduction: The conformational change activates intracellular signaling pathways. For example, the activation of GPCRs leads to the generation of second messengers like cAMP.
4. Cellular Response: The signal transduction cascade ultimately results in a specific cellular response, such as gene expression, ion channel opening, or metabolic changes.
