EXERCISE NO.
CELL MEMBRANE
BANUELOS, FERNANDEZ, JAYME, TINDOC
CELL
MEMBRANES
In the latter part of the
nineteenth century, scientists
discovered that the cell
membrane is selectively
permeable, meaning that some
molecules are able to cross the
cell membrane while others are
prevented from crossing the
membrane.
MEMBRANE TRANSPORT
Diffusion Diffusion is defined as the movement of
solute molecules from an area of higher
concentration to an area of lower
concentration.
OSMOSIS
Osmosis is the movement of water
molecules across a semipermeable
membrane, such as a cell membrane, from
an area of lower solute concentration to
an area of higher solute concentration.
LEARNING OBJECTIVES
TO HAVE A HANDS-ON EXPERIENCE WORKING WITH THE
01 HYDROPHOBIC AND HYDROPHILIC NATURE OF THE CELL
MEMBRANE AND MEMBRANE PROTEINS AS CHANNEL
02
TO DETERMINE THE STRENGTH OF THE MEMBRANE BY
TESTING THE SOLUBILITY OF LIPIDS TO DIFFERENT
ALCOHOL SOLUTIONS.
03 TO CONDUCT AND MAKE THEIR OWN
INVESTIGATION/EXPERIMENT TO APPLY THE CONCEPT
OF TRANSPORT OF SUBSTANCES IN CELL MEMBRANES.
ACTIVITIES
Cell Membrane:
Exploring Its Lipid Solubility of
Hydrophobic and
Egg Experiment
Membranes
Hydrophilic Properties
ACTIVITY A ACTIVITY B ACTIVITY C
CELL MEMBRANE:
EXPLORING ITS HYDROPHOBIC AND
HYDROPHILIC PROPERTIES
PROPERTIES
FLEXIBLE
SELF-REPAIR
FUSION FISSION
Fusion is the coming Fission is a cellular process
together of two different that occurs most frequently
cells, organelles, or in prokaryotic organisms
membranes into one (like bacteria) and some
cohesive unit. unicellular eukaryotes. It is
the division of a single cell
into two or more daughter
cells.
PHAGOCYTOSIS PINOCYTOSIS
Phagocytosis is a process The process of engulfing tiny
whereby cells, usually liquid droplets and dissolved
specialized solutes
immune cells (like from the environment into
macrophages), engulf and tiny vesicles is known as
digest big particles, pinocytosis.
such as bacteria, dead cells,
or foreign object
TAKEAWAY
Some specialized proteins
embed within the lipid bilayer,
Cell membranes are not
giving the membrane unique
static, they bend, and flex
properties.
in order to adapt, to
Channel proteins are one
changing conditions.
example. They form a
Attraction between
passageway for large or
phospholipids allows cell
electrically charged molecules
membranes to repair.
to pass
through the membrane.
RED ONION CELLS
LIPID SOLUBILITY OF MEMBRANES
HYPOTHESIS
We hypothesize that the
effects of the five different
alcohols (methanol, ethanol,
n-propanol, n-butanol, and n-
amyl alcohol) on red onion
cells will vary based on their
chemical properties,
including solubility and
ability to disrupt the cell
membrane.
ALCOHOL SOLUTIONS
01 02 03 04 05
METHANOL ETHANOL N-PROPANOL N-BUTANOL N-AMYL
ALCOHOL
UNDILUTED ALCOHOLS
Undiluted alcohols, in With undiluted (full-
the context of the strength) alcohols, the
previous explanations, time it takes to affect
refer to alcohols in the onion cells will likely
their full, original be relatively quick.
concentration and These alcohols are
strength, without any highly effective at
added water or disrupting the cell
solvent. membrane
1/2 DILUTION
A 1/2 dilution of alcohols means
that the alcohol has been mixed A 1/2 dilution of the alcohols
with an equal volume of a diluent, will slow down the process
typically water. In the context of compared to undiluted
the five alcohols (methanol,
alcohols. It may take more
ethanol, n-propanol, n-butanol,
and n-amyl alcohol) and their
time for the alcohols to
effects on red onion cells, a 1/2 have a noticeable effect on
dilution results in the alcohol the onion cells, as the
being at half its original concentration is lower.
concentration.
1/4 DILUTION
With a 1/4 dilution, the time it This dilution makes the
takes to affect the onion cells alcohols less harmful to the
will be further extended. The cells and their pigments
weaker concentration will compared to more
result in even milder effects, concentrated solutions.
and The process will be
notably slower than with
undiluted or 1/2 diluted
alcohols.
RED ONIONS UNDER
THE MICROSCOPE
RED ONION RED ONION RED ONION RED ONION
WITHOUT ALCOHOL WITH UNDILUTED WITHOUT ALCOHOL WITH UNDILUTED
ETHANOL N-BUTANOL
RED ONIONS UNDER
THE MICROSCOPE
RED ONION RED ONION RED ONION RED ONION
WITHOUT ALCOHOL WITH UNDILUTED WITHOUT ALCOHOL WITH UNDILUTED
N-PROPANOL METHANOL
RED ONIONS UNDER
THE MICROSCOPE
RED ONION RED ONION
WITHOUT ALCOHOL WITH UNDILUTED
AMYL ALCOHOL
CONCLUSION
Among the alcohols, methanol typically affects cells the fastest. This is
because methanol is highly polar and soluble in both water and lipids,
allowing it to rapidly penetrate the lipid bilayer of cell membranes.
N-amyl alcohol is likely to affect cells the slowest. This is because n-
amyl alcohol has a longer hydrophobic tail compared to the other alcohols,
and it is less soluble in both water and lipids.
The actual timeframes for these effects can vary depending on factors
such as the specific experimental conditions, the health and vitality of the
onion cells,closely linked to the chemical properties of these alcohols and
their concentration, and the measurement techniques used to assess changes
in the cells. It's important to monitor the cells carefully and observe any visible
alterations in their structure or integrity over time during the experiment.
EGG EXPERIMENT
PROCEDURES:
1. DESHELL
THE EGGS
2CH3COOH + CaCO3
Ca(CH3COO)2 + H2O + CO2
PROCEDURES:
1. RESET THE
EGGS
White membrane that will act
as a selectively permeable
membrane like the cell
membrane in humans.
Coke solution Coffee solution Zonrox solution
Orange Juice Baking soda
solution solution
HYPOTHESIS:
Deshelled eggs will simply
pop when soaked to
different solutions with
varying pH levels
RESULTS AND DISCUSSION
CONCLUSION
The conducted experiment were able to help
visualize and understand these fundamental
biological and chemical processes of osmosis
and diffusion. It was observed that different
solutions can create different outcomes,
providing a hands-on way to learn about these
concepts.
THANK'S
