Question

33) Which of the following is most likely true of a protein that cotransports glucose and sodium ions into the intestinal cells of an animal? A) Sodium and glucose bind to the same site on the cotransporter. B) Transport of glucose against its concentration gradient provides energy for uptake of sodium ions against the electrochemical gradient. C) Sodium ions can be transported whether or not glucose is present outside the cell, but glucose transport requires cotransport of sodium ions. D) Transport of sodium ions down their electrochemical gradient facilitates the transport of glucose against its concentration gradient. E) Following transport of sodium ions into the cell, the cotransporter can also transport potassium ions out of the cell. 34) The phosphate transport system in bacteria imports phosphate into the cell even when the concentration of phosphate outside the cell is much lower than the cytoplasmic phosphate concentration. Phosphate import depends on a pH gradient across the membrane-more acidic outside the cell than inside the cell. Phosphate transport is an example of A) passive diffusion. B) facilitated diffusion. C) active transport D) cotransport. E) receptor-mediated endocytosis. 35) What is the voltage across a membrane called? A) water potential B) chemical gradient C) membrane potential D) osmotic potential E) electrochemical gradient 36) The sodium-potassium pump is called an electrogenic pump because it

Answer 1

Q33) D. Transport of sodium ions down their electrochemical gradient facilitates the transport of glucose against its concentration gradient.

Na-glucose co-transport is a type of active transport in which the energy generated from the transport of sodium is used in the transport of glucose.

Q34) d. cotransport.

Cotransport need concentration gradient of H+ ions across the membrane for it to transport phosphate inside the cell.

Q35) C. membrane potential.

membrane potential is a concentration gradient across the membrane.