BIO Lec 10

When placed in a hypertonic solution, animal cells a. shrink. b. swell. c. burst. d. transport water out e. concentrate.

a. shrink.

Osmosis is a specific form of -diffusion -pinocytosis -active transport -secondary active transport -movement of water by carrier proteins

diffusion

Active transport usually moves molecules A) in the same direction as does diffusion. B) in the opposite direction as does diffusion. C) in a direction that tends to bring about equilibrium. D) toward higher pH. E) toward higher osmotic potential.

B) in the opposite direction as does diffusion.

For each molecule of ATP consumed during active transport of sodium and potassium, A) 2 sodium ions are imported and 3 potassium ions are exported. B) 2 sodium ions are imported and 1 potassium ion is exported. C) 1 potassium ion is imported and 3 sodium ions are exported. D) 2 potassium ions are imported and 3 sodium ions are exported. E) 3 potassium ions are imported and 2 sodium ions are exported.

D) 2 potassium (K) ions are imported and 3 sodium (Na) ions are exported.

Osmosis ... -Helps plant cells maintain turgor pressure -Moves macromolecules from one cell to another -Facilitated the "flipping" of proteins from one side of the membrane to the other -Keeps concentrations uniform in all cells -Causes cells to lose water when they are placed in a hypotonic solution

Helps plant cells maintain turgor pressure

Phagocytosis, pinocytosis, and receptor-mediated endocytosis all involve a. the intake of large particles. b. invagination of the plasma membrane. c. the export of macromolecules. d. the presence of receptor proteins. e. the intake of fluids by the cell.

invagination of the plasma membrane.

Osmosis moves water from a region of _______ to a region of _______. a. high concentration of dissolved material; low concentration of dissolved material b. low concentration of dissolved material; high concentration of dissolved material c. hypertonic solution; hypotonic solution d. negative osmotic potential; positive osmotic potential e. low concentration of water; high concentration of water

low concentration of dissolved material; high concentration of dissolved material

The difference between osmosis and diffusion is that a. diffusion is passive transport, whereas osmosis is active transport. b. only in diffusion do molecules move from areas of high concentrations to areas of low concentration. c. only diffusion refers to the movement of materials across a semipermeable membrane. d. osmosis refers specifically to the movement of water, whereas diffusion is the movement of molecules. e. the process of osmosis varies according to the kinds of particles present.

osmosis refers specifically to the movement of water, whereas diffusion is the movement of molecules.

If a red blood cell is placed in an isotonic solution, it will -shrivel -swell and burst -shrivel and then return to normal -swell and then return to normal -take up and release water at equal rates

take up and release water at equal rates

The existence of a concentration gradient of glucose across a membrane means that -there is a high concentration of glucose on both sides of the membrane -the glucose molecules are more crowded on one side of the membrane than on the other -there is a high concentration of water on both sides of the membrane -the glucose molecules are chemically more tightly bonded on one side than on the other -there are more glucose molecules within the membrane than outside of the membrane

the glucose molecules are more crowded on one side of the membrane than on the other

Which of the following statements about cholesterol molecules is true? a. They help hold a membrane together. b. They transport ions across membranes. c. They attach to carbohydrates. d. They disrupt membrane function. e. They alter the fluidity of the membrane.

They alter the fluidity of the membrane.

When a severely dehydrated patient is brought to the hospital, an IV of normal saline is started immediately. Distilled water is not used because a. it would cause water to leave the cells of the patient and the cells would collapse. b. nutrients are provided by the saline. c. it would cause the patient's blood cells to swell and eventually burst. d. normal saline is more economical. e. the distilled water might be contaminated by bacteria.

c. it would cause the patient's blood cells to swell and eventually burst.

When placed in water, wilted plants lose their limpness because of a. active transport of salts from the water into the plant cells. b. active transport of salts into the water from the plant cells. c. osmosis of water into the plant cells. d. osmosis of water from the plant cells. e. diffusion of water from the plant cells.

c. osmosis of water into the plant cells.