QuestionSBA
QuestionChoice
Myosin light chain kinase needs to be phosphatised into myosin light chain phosphatase before it can activate myosin. This has no role in unblocking the binding sites of actin.
10023513
d
Myosin light chain kinase
QuestionChoice
Protein kinase C can independently activate myosin light chain kinase, without the need for the calcified calmodulin. Myosin light chain kinase needs to be phosphatised into myosin light chain phosphatase before it can activate myosin.
10023514
e
Protein Kinase C
QuestionChoice
Myosin light chain phosphatase causes the activation of myosin which binds to actin causing smooth muscle contraction.
10023511
b
Myosin light chain phosphatase
QuestionChoice
This is the correct answer as calcified calmodulin binds to calponin to unblock actin-binding sites and myosin light chain phosphatase to activate myosin. The binding of myosin to actin causes smooth muscle contraction.
10023510
a
Calponin
QuestionChoice
Calmodulin is the molecule that once calcified, activates both calponin and myosin light chain phosphatase, which in turn causes smooth muscle contraction.
10023512
c
Calmodulin
Concept
Chapter
2693
5683
Gastric structure and function
Topic
149
Gastro-intestinal physiology
17100
A 53-year-old male comes into the clinic expressing pains in his stomach. He describes it as waves of squeezing pains. The doctor explains that it is his intestines undergoing peristalsis which is where the smooth muscle in the intestines contract in waves.

With regards to calcium-dependent smooth muscle contraction, what molecule unblocks the binding sites of actin?
a