MCDB 1150 EXAM 3 CU BOULDER ACTUAL

MCDB 1150 EXAM 3 CU BOULDER (ACTUAL / )

QUESTIONS & 100% VERIFIED ANSWERS

• A patient was involved a serious accident and lost a large

quantity of blood. In an attempt to replenish body fluids, distilled water (equal to the volume of blood lost) is added to the blood directly via one of his veins.What will be the most probable result of this transfusion?

a) It will have no unfavorable effect as long as the water is

free of viruses and bacteria.

b) The patient's red blood cells will shrivel up because the

blood has become hypotonic compared to the cells.

c) The patient's red blood cells will swell and possibly burst

because the blood has become hypotonic compared to the cells.

d) The patient's red blood cells will shrivel up because the

blood has become hypertonic compared to the cells.

e) The patient's red blood cells will burst because the blood

has become hypertonic compared to the cells. - ---Answers-- -c) The patient's red blood cells will swell and possibly burst because the blood has become hypotonic compared to the cells.

Which of the following correctly depicts the relative rate of diffusion of the listed molecules (from high to low) across a pure phospholipid bilayer?

a) RNA > Ca2+ > glucose > ethanol > N2 > water 1 / 3

b) N2 > ethanol > water > glucose > Ca2+ > RNA

• water > N2 > ethanol > Ca2+ > RNA > glucose
• ethanol > N2 > water > glucose > Ca2+ > RNA - ---Answers-

--b) N2 > ethanol > water > glucose > Ca2+ > RNA

Which of the following is true of osmosis?

a) Osmosis is an energy-demanding or "active" process.

b) In osmosis, water moves across a membrane in one

direction

c) In osmosis, water moves across a membrane in both

directions

d) In osmosis, solutes move across a membrane in one

direction

e) In osmosis, solutes move across a membrane in both

directions

f) In osmosis, water and solutes move across the membrane

in the same direction - ---Answers---c) In osmosis, water moves across a membrane in both directions

• Which of the following means of transport would most likely

be used for moving a medium-sized polar molecule (like a monosaccharide or an amino acid) from a low concentration on the outside of a cell to a high concentration on the inside of a cell?

• passive transport
• active transport through a "pump" protein
• facilitated diffusion via a transporter protein 2 / 3

• diffusion through an ion channel protein - ---Answers---b)

active transport through a "pump" protein

• Which of the following statements about diffusion is false?

a) Diffusion is the spontaneous movement a solute from a

region of low to high concentration.

b) Passive diffusion results in the net movement of molecules

from high to low concentration

c) Diffusion results in molecules being in a state of increased

disorder

d) Diffusion through membranes is decreased by the presence

of cholesterol - ---Answers---a) Diffusion is the spontaneous movement a solute from a region of low to high concentration.

• The Na+

/K+ pump is an integral membrane protein that simultaneously moves Na+ ions out of the cell and K+

ions into the cell. This requires energy because:

• the membrane is impermeable to charged molecules such

as Na+ and K+

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