Answer to Question #105076 in Biology for Kylie

Question

What are the protein structures called that are expressed within the cell membranes and
interact with endogenous signalling molecules or some drugs to initiate an intracellular
response?
1. Enzymes
2. Hormones
3. Ligands
4. Receptors

Answer 1

4. Receptors.

Receptors are transmembrane proteins that interact with specific ligands and drugs outside the cell and activate specific signaling pathways inside the cell in response to the binding. This process activates and intracellular response to certain factors.