EXPT 2: TRANSPORT ACROSS THE MEMBRANE Flashcards
allows two-way traffic of nutrients and waste needed to sustain metabolism
cell membrane
factors affecting diffusion
Magnitude of the concentration gradient
Size and shape of particles
temperature
composition of the cell membrane
- 55% proteins
- 25% phospholipids
- 13% cholesterol
- 3% carbohydrates
- 4% other lipids
allows certain substances
to pass through while restricting others
semi-permeable
The net movement of molecules or ions from
a region of higher concentration to a region of lower concentration
diffusion
The simple diffusion of a solvent (e.g., water)
across a membrane that is more permeable
to the solvent than to the solute
osmosis
The force needed to prevent osmosis
Osmotic Pressure
___________ temperature
increases the ________________ of particles,
leading to _______ diffusion
increased, kinetic energy, faster
Osmotic pressure always moves water
toward the
hypertonic side
Are proteins present in the dialysis experiment?
No, proteins are absent as the cellophane does not allow larger molecules to pass through. Only sugars are present.
A property of a fluid that causes its surface to
contract and behave as if it is enclosed in an
elastic membrane
Surface Tension
Cause of Surface Tension
Strong intermolecular forces between
molecules, such as hydrogen bonding in
water
products that are effective in lowering surface tensions
soap, detergents, and salts of bile acids
TRUE OR FALSE
higher temperatures
generally result in a faster diffusion
rate.
TRUE
Lipid bilayer of the cell membrane is composed of _____ hydrophilic head and ______hydrophobic tails.
one, two
often used
in medical settings to remove waste
products from the blood when the
kidneys are no longer able to perform
their function.
dialysis
helps maintain the cell’s shape and prevent it from bursting due to the internal pressure generated by the
cell’s metabolic processes.
surface tension
progressive condition characterized
by gradual loss of kidney function over
time.
renal insufficiency/chronic kidney disease (CKD)
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.
dialyzer
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.
hydrophobic head, hydrophilic tail
a flexible,
biconcave disk-shaped cell that
carries oxygen in the blood
red blood cell (rbc)
Water will move OUT of the cell and
into the surrounding solution to
equalize the solute concentrations on
both sides of the cell membrane.
hypertonic
Water will move INTO the cell and
swell it up, potentially causing the cell
to burst by increasing the pressure
inside the cell.
hypotonic
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.
isotonic
surface tension leads to
formation of drops, bubbles, and meniscus
capillarity
absorption of liquids by porous
ability to wet surface
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
Tonicity
three types of tonicity
hypotonic
hypertonic
isotonic
