Why do ion channels not function like open pores? What is membrane potential? How do K+ leak channels work? Why is the membrane potential of a resting cell negative? What is patch clamp recording? What is one of the major insights gained from patch clamp reporting experiments? Compare and contrast the three types of gated ion channels. Be familiar with the different parts of a neuron. During an action potential, what happens to the membrane potential, voltage-gated Na+ channels, Na+ ions, voltage gated K+ channels, K+ ions, and Na+-K+ ion pumps? When an action potential reaches a synapse, what happens to the Ca2+ channels, Ca2+ ions, neurotransmitters, transmitter-gated ion channels, and the post synaptic neuron? What effect do excitatory or inhibitory neurotransmitters have on postsynaptic cells? What is an example of a mechanically gated ion channel? Solution 1.Excitable cells, such as fast-acting neurons and muscle cells, have specialized channels that open in response to a signal and permit rapid ion movement across the cell membrane. The opening of just a single ion channel alters the electrical charge on both sides of the membrane. The resulting charge differential then causes adjacent voltage-sensitive channels to open in chain-reaction fashion, creating a self-propagating electrical signal that travels down the entire length of the cell. Sometimes, this sequence of events is triggered when a chemical signal — such as a neurotransmitter — binds to an ion channel receptor on cell\'s surface. Other times, a cell\'s ion channels open in response to mechanical (rather than chemical) stimuli. 2.In cells of all types, there is an electrical potential difference between the inside of the cell and the surrounding extracellular fluid. This is termed the membrane potential of the cell. When a nerve or muscle cell is at \"rest\", its membrane potential is called the resting membrane potential. In a typical neuron, this is about –70 millivolts (mV). The minus sign indicates that the inside of the cell is negative with respect to the surrounding extracellular fluid. 3.The leak channels allow K+ to move across the cell membrane down their gradients (from a high concentration toward a lower concentration). With the combined ion pumping and leakage of ions, the cell can maintain a stable resting membrane potential and create membrane potential of a resting cell negative. 4.Patch clamp recording is an extremely useful technique for investigating the biophysical properties of the ion channels that control neuronal activation. The procedure involves pressing a glass micropipette against a cell in order to isolate a small “patch” of membrane that contains one or more ion channels. The experimental setup further allows scientists to “clamp” the electrical environment of the patched area by precisely controlling the voltage across the cell membrane, which, depending on the ion channels present, impacts the flow of ions through the membrane and allow for int.