EXPT 2: TRANSPORT ACROSS THE MEMBRANE

Question 1

allows two-way traffic of nutrients and waste needed to sustain metabolism

Answer 1

cell membrane

Question 2

factors affecting diffusion

Answer 2

Magnitude of the concentration gradient
Size and shape of particles
temperature

Question 3

composition of the cell membrane

Answer 3

• 55% proteins
• 25% phospholipids
• 13% cholesterol
• 3% carbohydrates
• 4% other lipids

Question 4

allows certain substances
to pass through while restricting others

Answer 4

semi-permeable

Question 5

The net movement of molecules or ions from
a region of higher concentration to a region of lower concentration

Answer 5

diffusion

Question 6

The simple diffusion of a solvent (e.g., water)
across a membrane that is more permeable
to the solvent than to the solute

Answer 6

osmosis

Question 7

The force needed to prevent osmosis

Answer 7

Osmotic Pressure

Question 8

___________ temperature
increases the ________________ of particles,
leading to _______ diffusion

Answer 8

increased, kinetic energy, faster

Question 9

Osmotic pressure always moves water
toward the

Answer 9

hypertonic side

Question 10

Are proteins present in the dialysis experiment?

Answer 10

No, proteins are absent as the cellophane does not allow larger molecules to pass through. Only sugars are present.

Question 11

A property of a fluid that causes its surface to
contract and behave as if it is enclosed in an
elastic membrane

Answer 11

Surface Tension

Question 12

Cause of Surface Tension

Answer 12

Strong intermolecular forces between
molecules, such as hydrogen bonding in
water

Question 13

products that are effective in lowering surface tensions

Answer 13

soap, detergents, and salts of bile acids

Question 14

TRUE OR FALSE
higher temperatures
generally result in a faster diffusion
rate.

Answer 14

TRUE

Question 15

Lipid bilayer of the cell membrane is composed of _____ hydrophilic head and ______hydrophobic tails.

Answer 15

one, two

Question 16

often used
in medical settings to remove waste
products from the blood when the
kidneys are no longer able to perform
their function.

Answer 16

dialysis

Question 17

helps maintain the cell’s shape and prevent it from bursting due to the internal pressure generated by the
cell’s metabolic processes.

Answer 17

surface tension

Question 18

progressive condition characterized
by gradual loss of kidney function over
time.

Answer 18

renal insufficiency/chronic kidney disease (CKD)

Question 19

In hemodialysis, blood is drawn from
a patient’s body and passed through a
_______, which is a device composed
of a semipermeable membrane, and
connected to a machine that controls
the flow of blood, pressure, and
temperature.

Answer 19

dialyzer

Question 20

When soap is added to water, the
_____ _________of the soap molecules interacts with the water
molecules, while the ___________ ______
interacts with the other component of
soap molecules.

Answer 20

hydrophobic head, hydrophilic tail

Question 21

a flexible,
biconcave disk-shaped cell that
carries oxygen in the blood

Answer 21

red blood cell (rbc)

Question 22

Water will move OUT of the cell and
into the surrounding solution to
equalize the solute concentrations on
both sides of the cell membrane.

Answer 22

hypertonic

Question 23

Water will move INTO the cell and
swell it up, potentially causing the cell
to burst by increasing the pressure
inside the cell.

Answer 23

hypotonic

Question 24

There will be NO NET movement of
water into or out of the cell, and the
red blood cell will maintain its normal
shape and volume.

Answer 24

isotonic

Question 25

surface tension leads to

Answer 25

formation of drops, bubbles, and meniscus
capillarity
absorption of liquids by porous
ability to wet surface

Question 26

refers to the ability of a solution to affect shape and volume of cells by altering the concentration of solutes inside and outside the cell

Answer 26

Tonicity

Question 27

three types of tonicity

Answer 27

hypotonic
hypertonic
isotonic