Question

Which of the following statements are incorrect about receptor proteins?

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

Answer 1

Answer: (B), (C)

The active site of receptor proteins opens on the inside region of the cell.

Analysing the options:

Option (A):
Receptors are proteins that are crucial to the body's communication process. The majority of receptor proteins are embedded in the cell membrane.

Hence, statement (A) is true.

Option (B):
The majority of receptor proteins are embedded in the cell membrane. Their small part possessing active site projects out of the surface of the membrane and opens on the outside region of the cell membrane.

Hence, statement (B) is incorrect.

So, option (B) is a correct answer.

Option (C):
Certain chemicals known as chemical messengers through which a message is transferred between two neurons to muscles, are received at the binding sites of the receptor proteins.

Hence, statement (C) is true.

Option (D):
The shape of the receptor site changes to accommodate a messenger, this brings about the transfer of messages into the cell by chemical messenger without entering the cell.

Hence, statement (D) is not true.

So, options (B) and (D) are the correct answers.