If the potassium leak channels are blocked, what will happen to the membrane pot
ID: 303198 • Letter: I
Question
If the potassium leak channels are blocked, what will happen to the membrane potential? (a) The interior of the cell will become less negative (b) The interior of the cell becomes less positive (c) The exterior of the cell becomes less negative (d) The exterior of the cell becomes less positive What would happen to the membrane potential if sodium ions were allowed to flow down their concent gradient? (a) The interior of the cell will become less negative (b) The interior of the cell becomes less positive (c) The exterior of the cell becomes less negative (d) The exterior of the cell becomes more positive 3. How can a presynaptic neuron increase the intensity of the signal it is transmitting? entration (a) Increase the amount of neurotransmitters secreted (b) Change the type of neurotransmitter released (c) Increase the frequency of the action potential (d) Initiate a passive spread signal 34. What is the effect of opening the voltage gated sodium channels on the membrane potential? (a) Makes the interior of the cell less negatively charged (b) Makes the interior of the cell more negatively charged (c) Makes the interior of the membrane less positive (d) None of the above 35. When an action potential starts at one end of an axon, can it run out of energy and not reach the other end? (a) Yes (b) No 36. The sodium-potassium pump establishes concentration gradients: (a) Of higher sodium concentrations inside the cell and higher potassium concentrations outside the cell (b) Of sodium and potassium but the area of their concentrations (inside or outside) depends on the needs of the cell (e) Of higher potassium concentrations inside the cell and higher sodium concentrations outside the cell (d) By pumping sodium outside the cell and potassium is cotransported out as well 37. ATP is required in the transport of (a) All molecules across a membrane (b) Molecules through a protein channel (c) Molecules to areas of lower concentrations (d) Molecules to areas of higher concentrations 38. The net movement of uncharged, polar molecules across a semipermeable membrane from a low concentration to a high concentration occurs by diffusion (a) True (b) False 39. Fluidity of phospholipid bilayer is increased (a) Cholesterol at certain temperatures (b) Double bonds between carbon atoms in the fatty acid tails (c) Shorter hydrophobic tails (d) All the above 40. All the following statements concerning tran smitter-gated ion channels are true EXCEPT: (a) Are Ligand-gated channels (b) Are Voltage-gated channels onvert the chemical signal neurotransmitter into an electrical signal (d) Are receptorsExplanation / Answer
31) potassium channel::--- these channels are most widely distributed type of ion channel and are found virtually in all living organisms. Biologically these channels act to set or reset the resting potential.
So if potassium leak is blocked then condition just similar to the a,d options so the so the membrane potential shifts from negative value to zero. This means depolarisation takes place.
32).b,c is the right answer. Na+ when flow down there concentration gradient so the accumulation of sodium ion will be high in cell. So above condition b,c, will be there.
33) perisynaptic neuronne:-- releases chemicals messengers like neurotransmitter into the synapse which is a gap between two neuronsn.
So when an action potential arrives at nerve end then the electric signal induces voltage gated Ca+ channels.
So above statement favours Option C. Because intensity of signal is fast then it cause earlier and signal at fast rate receiving and sending.
34). Option is b when sodium gated channels it will neutralise outer negative enviourement and subconsequently inner envoenvioure will get become neutral.