All of the following are examples of primary active transpo, except:: (A) The Na+/K+ ATPase in the red cell membrane, (B) The H+/K+ ATPase in the parietal cell of stomach, (C) Na+/ glucose sympoer, (D) SERCA in the skeletal muscle
Answer is C. Sodium/glucose sympoer is an example of secondary active transpo. SERCA: Sarcoplasmic Endoplasmic Reticulum Ca++ ATPase. It transpos two molecules of Ca++ for each molecule of ATP hydrolysed. Ca++ pumped out of the sarcoplasm, into the longitudinal tubules, to decrease the sarcoplasmic and thus causes muscle relaxation.