The Na-Ca* exchanger is used to help regulate cardiac muscle function. It transports three Na into the cell and one Ca+ out of the cell in every cycle. What kind of transporter is the Na*-Ca+ exchanger? Digoxin is a drug used to treat heart failure by blocking the Na-K* pump in cardiac cells. How would inhibition of the Na*- K* pump alter the intracellular concentration of Ca+? Choose one: O A. Intracellular Ca2+ would not be altered by inhibiting the Na-K+ pump. O B. Intracellular Ca2+ levels would decrease when the Na-K* pump is inhibited. OC. Intracellular Ca2+ levels would increase when the Na-K* pump is inhibited. The animated figure shows a passive transporter transporting solute across the membrane. The GLUT2 transporter is a passive glucose transporter found on the plasma membrane in liver cells. When blood glucose levels are high after a meal, glucose is transported by GLUT2 into liver cells for storage. When blood glucose levels are low, glucose can be transported out of the liver using the same GLUT2 transporter. How can the same transporter transport glucose in one direction in some conditions and in the opposite direction in other conditions? Choose one: O A. The GLUT2 transporter imports glucose into the cell in a passive manner and uses the energy of ATP to export glucose. B. The liver cell can flip the GLUT2 transporter so glucose is transported the opposite way when needed. C. The GLUT2 transporter transports glucose with the concentration gradient so it will transport it both into and out of the cell in the direction of the gradient. D. The GLUT2 transporter forms a pore across the membrane for glucose to flow through.