Protein-Mediated Transport

Practice: A transporter moves Na+, K+, and Cl- into the cell. What type of protein-mediated transport does this channel perform? (Hint: [Na+] is higher outside the cell, [K+] and [Cl- ] are higher inside the cell).

Practice: Nicotinic acetylcholine receptors (nAchRs) are inserted in the membranes of skeletal muscle fibers. When they bind to acetylcholine, a channel within them opens and allows Na+ and K+ to cross the skeletal muscle cell membrane. Which of the following describes the category into which nAchRs fit?

Practice: Parietal cells of the stomach express H+/K+ ATPase proteins. These proteins use energy from the hydrolysis of ATP to pump one H+ out of the cell into the stomach while, at the same time, bringing one K+ from the stomach into the cell. Which of the following accurately describes this type of transport?