Final answer:
Ligand-gated sodium channels in cell membranes do have receptor sites for acetylcholine and open to allow specifically selected ions, such as Na+, Ca2+, and K+, to pass through when acetylcholine binds to them.
Step-by-step explanation:
True or False: The sodium channels in the cell membrane have receptor sites for acetylcholine. The answer to this question is True. The sodium channels referred to here are likely ligand-gated channels, which indeed have receptor sites for neurotransmitters such as acetylcholine. When acetylcholine binds to these receptor sites on the extracellular surface of the channel protein, a conformational change occurs in the channel protein that allows it to open and cations such as sodium (Na+), calcium (Ca2+), and potassium (K+) to pass through, modifying the membrane potential.
This channel protein spans the cell membrane, with hydrophobic amino acids interacting with the phospholipid fatty acid tails and hydrophilic amino acids lining the channel's interior, allowing for the passage of ions. These types of receptors enable rapid changes in membrane potential as part of cell signaling processes, particularly in neurons and muscle cells.