Phospholipid Bilayer Question

Question

Question: At the start of an experiment, a phospholipid-bilayer membrane that contains the glucose transporter (GLUT-1) but no other proteins separates a 1-liter solution of 1M NaCl (on the right) from a 1-liter solution of 1M glucose (on the left). By the end of the experiment,

a. there will be more water on the left side of the membrane than on the

right side.

b. there will be more water on the right side of the membrane than on the left.

c. there will be the same amount of water on both sides of the membrane.

d. water molecules will no longer cross the membrane.

e. not enough information

Answer 1

By the end of the experiment, there would be more water on the right side than on the left since 1 M NaCl is actually about 2 OsM and 1 M glucose is about 1 OsM so tonicity is greater on the right side and water would move in that direction by osmosis.

It is also true that water molecules will no longer cross the membrane in a NET movement. They will still cross, but at the same rate in both directions.