To figure out the incorrect statements about the receptor

proteins, let us first know about them in a nutshell

• They are crucial to body’s communication process

• Majority of these are embedded in cell membranes

• Their small part possessing active site projects out of the surface of the membrane and opens on the outside region of the cell membrane when they are embedded in cell membrane

• Certain chemicals known as chemical messengers through which message is transferred between two neurons or between neurons to muscle are received at the binding sites of the receptor proteins

• Shape of the receptor site changes to accommodate a messenger, this brings about the transfer of message into the cell by chemical messenger without entering the cell.

• Large number of different receptors in the body with different shape, structure and amino acid composition leads to selectivity for chemical messenger over other.

Hence, from the above discussion we can conclude that following according to question options (ii) and (iv) are correct and options (i) and (iii) are incorrect.