PHYSIOLOGY
MUSCLE STRUCTURE FUNCTION
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
What is NOT a component of muscle relaxation
|
|
Ca++ binds with tropomyosin
|
|
|
Active sites on actin are covered, no cross-bridge interaction
|
|
|
Sarcoplasmic reticulum recaptures Ca++
|
|
|
ACh is broken down by AChE
|
Explanation:
Detailed explanation-1: -(a) In the absence of Ca2+, tropomyosin prevents the binding of myosin heads to actin. (b) When the [Ca2+] rises, Ca2+ binds to a subunit of troponin, which causes the tropomyosin to shift slightly into the groove of the actin filament. The shift in position of tropomyosin allows the myosin heads to bind to actin.
Detailed explanation-2: -This model suggests that relaxation occurs when tropomyosin in the “relaxed” position physically blocks the binding of the myosin cross-bridge to actin.
There is 1 question to complete.