Hundreds of mutations have been identified in RyR1 that contribute to multiple muscular diseases. Assume that a new mutation was discovered that causes this receptor to continually remain open. Based on what you know about the function of this receptor, how would you expect this new mutation to impact contraction?
(a)-This mutation will increase the sensitivity of the DPH receptor to voltage changes, which will induce continued muscle contraction.
(b)This mutation will decrease the sensitivity of the DPH receptor to voltage changes,which will prevent muscle contraction.
(c)-This mutation will decrease levels of calcium in the sarcoplasm, which will prevent muscle contraction.
(d)-This mutation will increase levels of calcium in the sarcoplasm, which will induce continued muscle contraction.

Among the mutations that cause muscular diseases, a new mutation makes the muscle receptor to be opened always. This can be stated that this function is of the receptor called sarcoplasmic reticulum. This structure in the cell of muscles is membrane bound and it conserves calcium mainly. The pumps that are used to maintain the calcium level is the SERCA. It has all in all thirteen subunits, of which calcium ions get attached to the subunits- M1-M10 and ATP gets bind to A, P and N subunits.

The cytosolic side of this pump gets bind with two calcium ions and an ATP molecule which keeps it open. The release of phosphate group by ATP changes the shape of pump. So, it is evident here that in this new mutation the pump receptor will be open.