Which of the following best describes how ACh changes the ion permeability of the sarcolemma? View Available Hint(s) O ACh activates acetylcholinesterase. O ACh binds to receptors in the junctional folds. O ACh entry into the axon terminal causes neurotransmitter release. O ACh entry into the muscle fiber causes Ca+ to be released by the sarcoplasmic reticulum. Use the provided terms to correctly complete each sentence. Terms may be used more than once. View Available Hint(s) K* ACh Na 3. Reset Help diffuses out of the muscle fiber through open chemically gated ion channels. binds to ACh receptors, causing them to open chemically gated ion channels. diffuses into the muscle fiber through open chemically gated ion channels. 4. The end plate potential is primarily, and most directly, caused by the movement of 32 Which of the following best describes the role of acetylcholinesterase molecules at the neuromuscular junction? View Available Hint(s) Acetylcholinesterase molecules close once ACh is released, which decreases the sarcolemma's permeability to Na' and K'. O Acetylcholinesterase binds ACh, preventing it from binding to chemically gated ion channels. O Acetylcholinesterase breaks down ACh, which allows chemically gated ion channels to close. O Acetylcholinesterase prevents Na* and K* from passing through chemically gated ion channels.