Question

In ion channel receptor c-terminus and nterminus are:

a. both inside cell
b. both outside cell
c. c-terminus inside and n-terminus ouside
d. c-terminus outside and nterminus inside

Answer 1

The C-terminus and N-terminus of ion channel-linked receptors can be either interior or exterior to the cell membrane, depending on the specific receptor. option c is correct.

Step-by-step explanation:

In ion channel-linked receptors, the location of the C-terminus and N-terminus can vary depending on the particular structure of the receptor. Generally, these receptors span the cell membrane so that part of the receptor is interior to the cell membrane, while another part is exterior to the cell membrane.

The binding of ions, such as Na+, typically occurs on the outer surface of the cell, whereas the binding of other ions, like K+, usually takes place on the inner surface of the cell. When a ligand binds to the extracellular region of the channel, a conformational change occurs that allows specific ions to pass through the channel, which is lined by hydrophilic amino acids to facilitate ion passage.

The n-terminus (amino-terminus) is the starting point of the protein, typically located outside the cell, while the c-terminus (carboxy-terminus) is the end of the protein, usually found inside the cell. This orientation is crucial for the proper functioning of ion channel receptors, as it determines how these proteins interact with signaling molecules and transmit signals across the cell membrane.