Which statement about calcium ions is true?

Question

Quizplus · Accepted Answer

Calcium ions are typically more concentrated outside the cell than in the cytoplasm. Active transport mechanisms such as the plasma membrane Ca2+-ATPase and the Na+/Ca2+ exchanger maintain this concentration difference. When calcium signals are needed within the cell, intracellular stores are accessed through the opening of channels and release of Ca2+. Inositol trisphosphate (IP3) is one signal that can cause this release, but other mechanisms can also trigger the process. Calcium ions are important second messengers in many cellular pathways.

Which Statement About Calcium Ions Is True