Question

Which of the following statements are incorrect about receptor proteins?

• A. Majority of receptor proteins are embedded in the cell membranes
• B. The active site of receptor proteins opens on the inside region of the cell
• C. Chemical messengers are received at the binding sites of receptor proteins
• D. Shape of receptor doesn't change during attachment of massenger

Answer 1

Answer: (B), (D)

The correct options are
B The active site of receptor proteins opens on the inside region of the cell
D Shape of receptor doesn't change during attachment of massenger

A receptor is a protein molecule usually found embedded within the plasma membrane surface of a cell that receives chemical signals from outside the cell. When such chemical signals bind to a receptor, they cause some form of cellular/tissue response, e.g. a change in the electrical activity of the cell. In this sense, a receptor is a protein molecule that recognises and responds to endogenous chemical signals, e.g. the acetylcholine receptor recognizes and responds to its endogenous ligand, acetylcholine. However sometimes in pharmacology, the term is also used to include other proteins that are drug targets, such as enzymes, transporters and ion channels.