Above is a two neuron chain: a pre-synaptic neuron and a post-synaptic neuron. 3
ID: 3476403 • Letter: A
Question
Above is a two neuron chain: a pre-synaptic neuron and a post-synaptic neuron. 36. Where would the "all or none" decision be made? 37. At what location(s) are ligand operated channels found? 38. At what location(s) are voltage operated channels found? 39. Specifically, where are calcium voltage operated channels found? 40. At what location(s) are Sodium-Potassium (Na+/K+) ATPases found? 41. Site where AChE is found. 42. At what location(s) could you detect an action potential? 43. At what location(s) would you detect local, or graded, potentials? 44. At what location(s) would curare target? 45. At what location(s) would lidocaine target? 46. At what location(s) would the botulinum toxin target?Explanation / Answer
36. The action potential is the all and none response. All and none response means that the amplitude and duration of the action potential remains the same. Action potentials are generated on postsynaptic neurons. Option is b.
37. The receptors for ligand operated ion channels are present on the plasmolemma, the nerve cell membrane. Binding of neurotransmitters to these receptors will open the channel due to conformational change, resulting in a flow of ions across the membrane. Option is a.
38. Voltage gated ion channels are found along the axon and the synapse. They propagate electrical signals across the membrane. Option is b, c and d
39. Calcium voltage operated channels are present on the membrane of excitable neurons. The not only alter membrane potential but also act as signaling entities such as gene transcription, neurotransmitter release, neurite outgrowth, and the activation of calcium-dependent enzymes. Option is d.
39. The sodium potassium ATPase is present at the site of voltage gated ion channels in the cell membrane. Option is a,b,c,d.
40. Acetylcholine esterase breaks down acetylcholine and is found at neuromuscular junction. Right option is e.
41. Action potential will be generated near the voltage gated channels. Activity of these channels will result in action potentials. Hence, b,c,d.
42. Local and graded potentials are generated due to summation of action of ligand-gated ion channel proteins. Hence, option is a.
43. Curare is a poison that inhibits acetylcholine receptors. Curare affects the stimulus (the EPSP) that initiates muscle action potential. Hence, it will target neuromuscular junction. Option is e.
44. Lidocaine blocks voltage gated sodium channels at the axon. This prevents generation of action potential. Option is b and c.
45. Botulinum toxin prevents the release of acetylcholine preventing muscle contraction. Hence, option is d.