Question

Ca2+ pumps in the plasma membrane and endoplasmic reticulum are important for _____________.

(a) maintaining osmotic balance
(b) preventing Ca2+ from altering the activity of molecules in the cytosol and from reacting with organic anions to form precipitate
(c) providing enzymes in the endoplasmic reticulum with Ca2+ ions that are necessary for their catalytic activity
(d) maintaining a negative membrane potential

Answer 1

Ca2+ pumps in the plasma membrane and endoplasmic reticulum prevent Ca2+ from altering the activity of molecules in the cytosol and from forming precipitate.

Step-by-step explanation:

Ca2+ pumps in the plasma membrane and endoplasmic reticulum are important for preventing Ca2+ from altering the activity of molecules in the cytosol and from reacting with organic anions to form precipitate. This is option (b) of the provided answer choices. These pumps actively transport Ca2+ ions against their concentration gradient, ensuring that the intracellular concentration of Ca2+ remains low and preventing undesirable reactions in the cell.