If the concentration of sugar molecules in water on side "A" of a selectively permeable membrane is 5 percent,and the concentration of sugar molecules in water on side "B" of a selectively permeable membrane is 15 percent,the water will
A) mostly move from side "B" to side "A" because the water concentration is higher on side"B." B) mostly move from side "A" to side "B" because the water concentration is higher on side"A." C) mostly move from side "A" to side "B" because the water concentration is higher on side"B." D) not move at all because the water concentrations are isotonic.
Phospholipids are large organic molecules with a hydrophilic,polar phosphate head connected to hydrophobic,nonpolar fatty acid tails.These molecules arrange themselves to form a mostly impermeable barrier between a liposome and its environment by lining up
A) hydrophilic head to hydrophilic head with the tails all facing outward from the center line of the membrane. B) hydrophobic tails facing each other at the center line of the membrane with the hydrophilic heads facing outward, away from the center line of the membrane. C) hydrophobic tails facing hydrophilic heads. D) hydrophilic tails facing hydrophobic heads with every other tail facing outward from the center line of the membrane.
Cheryl is in a lab attempting to prepare a slide of cow blood for observation in a wet mount.She places a small drop of the blood on a slide,adds a drop of strong saline (salt)solution,and then covers all of it with a coverslip.After returning to her desk,she observes the slide with her microscope and notices that all of the red blood cells (RBCs)do not look like the nice round donut-shaped cells in her lab manual.Instead,the RBCs look very shriveled up.Her lab partner,Derek,has also made a slide,but the RBCs on his slide do look like the ones in the lab manual.Derek used a more dilute solution of saline but the same vial of blood. The most plausible explanation for the appearance of the blood cells on Cheryl's slide is that the
A) saline she used was hypotonic to the RBCs; this resulted in water osmosing through the RBC plasma membrane mostly into the cells. B) saline she used was isotonic to the RBCs; this resulted in water osmosing through the RBC plasma membrane into and out of the cells at an equal rate. C) saline she used was hypertonic to the RBCs; this resulted in water osmosing through the RBC plasma membrane mostly out of the cell. D) RBCs were hypertonic to the saline; this resulted in water osmosing through the RBC plasma membrane mostly into the cells.