quiz 10

When a severely dehydrated patient is brought to the hospital, an IV of normal saline is started immediately. Distilled water is not used because

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

For each molecule of ATP consumed during active transport of sodium and potassium, there is an import of ____ ions and an export of ____ ions.

two K+; three Na+

Osmosis is a specific form of

diffusion

Osmosis

helps plant cells maintain turgor pressure

Active transport usually moves molecules

in a direction opposite to the one in which diffusion moves them

phagocytosis, pinocytosis, and receptor-mediated endocytosis all involve

invagination of the plasma membrane

Osmosis moves water from a region of _______ to a region of _______.

low concentration of dissolved materials; high concentration of dissolved materials

When placed in water, wilted plants lose their limpness because of

osmosis of water into the plant cells

The difference between osmosis and diffusion is that

osmosis refers specifically to the movement of water, whereas diffusion refers to the movement of any type of molecule

When placed in a hypertonic solution, animal cells

shrink

If a red blood cell is placed in an isotonic solution, it will

take up and release water at equal rates

The existence of a concentration gradient of glucose across a membrane means that

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?

they alter the fluidity of the membrane