Binding of myosin to actin in skeletal muscle cells does not normally take place in the absence of Ca2+.
Indicate whether the statement is true or false.
(
Question 2) Organophosphate nerve gases induce paralysis by blocking neural stimulation of the neuromuscular junctions, while botulinum toxin produces the same effect by inhibiting acetylcholinesterase.
Indicate whether the statement is true or false.
(
Question 3) The site of Ca2+ storage in muscle cells is the lateral sacs of the transverse tubules.
Indicate whether the statement is true or false.
(
Question 4) Excitation-contraction coupling refers to the binding of energized myosin to actin.
Indicate whether the statement is true or false.
(
Question 5) Curare blocks neuromuscular transmission by preventing the release of neurotransmitters from the motor neuron.
Indicate whether the statement is true or false.
(
Question 6) Actin is an ATPase enzyme.
Indicate whether the statement is true or false.
(
Question 7) The binding of ATP to myosin causes an allosteric change in myosin's actin-binding site such that the affinity of myosin for actin is decreased.
Indicate whether the statement is true or false.
(
Question 8) The step of the cross-bridge cycle that immediately follows the attachment of ATP to the myosin head is referred to as the powerstroke.
Indicate whether the statement is true or false.
(
Question 9) The phenomenon of rigor mortis demonstrates that myosin can remain bound to actin in the absence of additional ATP, but the bond cannot then be broken.
Indicate whether the statement is true or false.
(
Question 10) The energy for muscle contraction is provided indirectly by the hydrolysis of ATP.
Indicate whether the statement is true or false.
Quick Reply
