question archive 1) During the rising phase of an action potential: A
1) During the rising phase of an action potential: A
Subject:BiologyPrice: Bought3
1) During the rising phase of an action potential:
A.the membrane becomes highly permeable to K+
B.the membrane becomes highly permeable to Na+
C.the membrane potential undergoes a rapid hyperpolarization
D.the membrane voltage moves rapidly towards Ek
E.both (B) and (D)
The following is a true statement regarding graded potentials:
A.graded potentials are not able summate
B.graded potentials cannot have sub-threshold amplitudes
C.graded potentials can only be excitatory
D.graded potentials cannot be recorded in the cell bodies of neurons
E.graded potentials propagate passively along dendrites
The structure of a voltage-dependent Na+ channel is best described as consisting of:
A.a single polypeptide with four membrane spanning domains each with six membrane spanning alpha-helices
B.a hetero-multimeric protein with four polypeptide subunits each with six membrane spanning alpha-helices
C.a single polypeptide with five membrane spanning domains
D.a hetero-multimeric protein with five polypeptide subunits
E.a single polypeptide with six membrane spanning alpha helices
Which of the following compounds would be expected to abolish the rising phase of the action potential of the squid axon:
A.tetrodotoxin (TTX)
B.tetra-ethyl ammonium (TEA)
C.botulinum toxin
D.(A) and (B) only
In the well characterized Gs coupled GPCR pathway, a slow modulating excitatory response to activation is mediated by:
A.the phosphorylation of K+ channels that closes the channels and causes membrane depolarization
B.the phosphorylation of K+ channels that opens the channels and causes membrane hyperpolarization
C.the phosphorylation of K+ channels that opens the channels and causes membrane depolarization
D.the phosphorylation of K+ channels that closes the channels and causes membrane hyperpolarization
