Ouabain is a specific inhibitor of the active transport of sodium ions out of the cell and is therefore a valuable tool in studi
es of membrane transport mechanisms. Which of the following processes in your own body would you expect to be sensitive to inhibition by ouabain? Explain your answer in each case.Part AFacilitated diffusion of glucose into a muscle cell Facilitated diffusion of glucose into a muscle cellYes; sodium ion cotransport is required for facilitated diffusion of glucose.No; sodium ion cotransport is required for simple diffusion of glucose, but not for facilitated diffusion of glucose.No; sodium ion cotransport is required for active transport of glucose, but not for facilitated diffusion of glucose.Part BActive transport of dietary phenylalanine across the intestinal mucosa Active transport of dietary phenylalanine across the intestinal mucosaYes; cotransport of sodium ions drives the inward movement of amino acids and can only occur if sodium ions are actively pumped back out again.No; the movement of amino acids depends on a potassium ion cotransport.No; the movement of amino acids depends on a calcium ion cotransport.Part CUptake of potassium ions by red blood cells Uptake of potassium ions by red blood cellsYes; uptake of potassium ions can occur only via a pump that couples the inward pumping of potassium ions to the outward pumping of sodium ions.No; uptake of potassium ions can occur only via a pump that couples the inward pumping of potassium ions to the outward pumping of calcium ions.No; uptake of potassium ions can occur only via a pump that couples the inward pumping of potassium ions to the outward pumping of protons.Part DActive uptake of lactose by the bacteria in your intestine Active uptake of lactose by the bacteria in your intestineYes; active uptake of sugars in bacteria is driven by a sodium ion cotransport.No; active uptake of sugars and amino acids in bacteria is driven by a proton gradient.No; active uptake of sugars and amino acids in bacteria is driven by a potassium ion cotransport
The bald eagle and the black bear are tetrapods, which means that they both have four limbs along with the digits. This shows that they both are the descendants of the four-limbed ancestors. However, the limbs of the bear and the bald eagle have different functions. The forelimbs of both these organisms serves different purpose. Hence, their limbs are homologous organs. The homologous organs are those which have the same ancestry but the functions are different.
