Which of the following are true in regard to Ca2+ in the cell? A. The large grad
ID: 255881 • Letter: W
Question
Which of the following are true in regard to Ca2+ in the cell?
A. The large gradient tending to drive Ca2+ into the cytosol from both the ER and plasma membranes leads to Ca2+ rushing into the cytosol when Ca2+ channels are activated.
B. The frequency of Ca2+ oscillation can code a specific cellular response.
C. Ca2+ directly activates PKA by releasing it from inhibitory subunits
D. Increased local Ca2+ opens nearby IP3 and Ryanodine receptors by calcium-induced calcium release.
E. Calcium ATPases in the plasma membrane and ER help to maintain low levels of calcium in the cytosol.
Explanation / Answer
Ans. E
(( two type of ATPase, in plasma membrane(PMCA) and in SER i.e (SERCA) they store back the calcium after muscles has contracted or when not further need of more calcium ))