chapter 3-plasma membrane

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Chapter 3Chapter 3

Movement of SubstancesMovement of Substances

across the Plasmaacross the PlasmaMembraneMembrane


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Learning outcomesLearning outcomes

At the end of this lesson, student will able to:At the end of this lesson, student will able to:

State the substances required by living cells.State the substances required by living cells.

State the substances that have to be eliminated from cells.State the substances that have to be eliminated from cells.

Explain the necessity for movement of substances acrossExplain the necessity for movement of substances acrossthe plasma membrane.the plasma membrane.

Identify the structure of plasma membraneIdentify the structure of plasma membrane

Describe the fluid-mosaic structureDescribe the fluid-mosaic structure


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Key TermsKey Terms

Active transport-pengangkutan aktifActive transport-pengangkutan aktif Crenation-Crenation- Deplasmolysis-Deplasmolysis- Facilitated diffussion-Facilitated diffussion- Flaccid-Flaccid- Haemolysis-Haemolysis-

Hydrolysis-Hydrolysis- Hydrophilic-Hydrophilic-


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Hydrophobic-Hydrophobic- Hypertonic-Hypertonic-

Hypotonic-Hypotonic- Isotonic-Isotonic- Osmosis-Osmosis- Passive transport-Passive transport-

Phospholipid-Phospholipid- Plasma membrane-Plasma membrane- Plasmolysis-Plasmolysis-

Semi-permeable-Semi-permeable-

Simple diffusion-Simple diffusion- Turgid-Turgid- Wilting-Wilting-


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3.1 Movement across the3.1 Movement across the

Plasma MembranePlasma Membrane

Necessities for the Movement of SubstancesNecessities for the Movement of Substances

across the Plasma Membraneacross the Plasma Membrane

Function of the Plasma MembraneFunction of the Plasma Membrane

The structure of the plasma membraneThe structure of the plasma membrane

The permeability of the plasma membraneThe permeability of the plasma membrane


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Necessities for the Movement ofNecessities for the Movement of

Substances across the PlasmaSubstances across the Plasma

MembraneMembraneTo transport nutrients into the cell.To transport nutrients into the cell. For gases exchangeFor gases exchangeTo excrete metabolic waste.To excrete metabolic waste.

To maintain the pH value and ionicTo maintain the pH value and ionicconcentration of the cell.concentration of the cell.

Secrete useful substances, for example,Secrete useful substances, for example,digestive enzymes and hormones.digestive enzymes and hormones.

To maintain a constant internalTo maintain a constant internalenvironment (homeostasis).environment (homeostasis).


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Function of the PlasmaFunction of the Plasma

MembraneMembrane

Protects the cell.Protects the cell.

Separates the intracellularSeparates the intracellular

components from the extracellularcomponents from the extracellular

environment.environment.

Controls what enters and exits theControls what enters and exits the

cellcell


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The structure of the plasmaThe structure of the plasma

membranemembrane


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Plasma membrane composed mainly ofPlasma membrane composed mainly ofphospholipidsphospholipids andand proteinsproteins..

In 1972, S. Singer and G. NicolsonIn 1972, S. Singer and G. Nicolsonintroduced theintroduced the fluid-mosaic modelfluid-mosaic model of theof themembrane structure.membrane structure.

Comprised of theComprised of the phospholipid bilayerphospholipid bilayerand various types ofand various types ofprotein moleculesprotein molecules..

MosaicMosaic-has various protein molecules-has various protein moleculesembedded in the phospholipid bilayer.embedded in the phospholipid bilayer.

Dyanamic & fluid- phospholipid moleculesDyanamic & fluid- phospholipid moleculescan move-giving the membrane itscan move-giving the membrane its fluidityfluidity& flexibility.& flexibility.


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Polar head~ hydrophilic (attract to water)Polar head~ hydrophilic (attract to water)

Non-polar tail~ hydrophobic (repelled byNon-polar tail~ hydrophobic (repelled by

water)water) CholesterolCholesterol~ stabilise &~ stabilise &

strengthen,flexible, less permeable to water-strengthen,flexible, less permeable to water-

soluble substances i.e. ions.soluble substances i.e. ions.

Pore proteinPore protein~ a protein molecule that has~ a protein molecule that hasa pore to provide a passage for a particulara pore to provide a passage for a particular

solute to pass through.solute to pass through.

Carrier proteinCarrier protein~ a protein molecule that~ a protein molecule that

has a shape that fits the shape of a specifichas a shape that fits the shape of a specific

molecule so that it can only carry specificmolecule so that it can only carry specific

molecules across the membrane.molecules across the membrane.


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fluid-mosaic modelfluid-mosaic model

Refers to the dynamic and fluidRefers to the dynamic and fluid

structure of protein moleculesstructure of protein molecules

that float and move freely in thethat float and move freely in the

phospholipid bilayer.phospholipid bilayer.


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Permeability of thePermeability of the

Phospholipids BilayerPhospholipids Bilayer

The permeability of the phospholipidsThe permeability of the phospholipids

bilayer is determined by:bilayer is determined by:

the size &the size &

the polaritythe polarity

of the substances pass through it.of the substances pass through it.

Selectively permeable or semi-permeableSelectively permeable or semi-permeable

Why do you think the plasma membraneWhy do you think the plasma membrane

semi-permeable?semi-permeable?


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Activity 1Activity 1

Label the structure of plasmaLabel the structure of plasma

membranemembrane


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Substances In and Out

through the Membrane


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Activity 2Activity 2

CrosswordCrossword


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Plant cell and animal cellPlant cell and animal cell

lab reportlab report AimAim

MaterialMaterial

ApparatusApparatus

Technique usedTechnique used

ProcedureProcedure

ObservationObservation

DiscussionDiscussion

ConclusionConclusion


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ProcedureProcedure

Put a drop of iodine on one side ofPut a drop of iodine on one side of

the cover slip.the cover slip.

A drop of iodine was putted on oneA drop of iodine was putted on one

side of the cover slip.side of the cover slip.


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Example:Example:

Aim: To study the structure of plant cellAim: To study the structure of plant cell

Materials: onion, iodine solution, distilled water andMaterials: onion, iodine solution, distilled water and

filter paperfilter paper

Apparatus: slides, cover slips, scalpel, forceps,Apparatus: slides, cover slips, scalpel, forceps,

dropper, mounted pin and light microscopedropper, mounted pin and light microscopeTechnique used: observation under light microscopeTechnique used: observation under light microscope


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ProcedureProcedure

1.1. A scale leaf is obtained from an onion bulb.A scale leaf is obtained from an onion bulb.

2.2. A pair of forceps was used to strip the transparentA pair of forceps was used to strip the transparentepidermis layer from the inner surface of the onionepidermis layer from the inner surface of the onionscale leaf.scale leaf.

3.3.

A drop of water was putted on the middle of the slideA drop of water was putted on the middle of the slideand the epidermis is place on the drop of water.and the epidermis is place on the drop of water.

4.4. The specimen was covered by using mounting needleThe specimen was covered by using mounting needlewith a cover slip at a 45 degree angle.with a cover slip at a 45 degree angle.


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5.5. A drop of iodine solution was added ontoA drop of iodine solution was added onto

one side of the cover slipone side of the cover slip

6.6. Filter paper was placed at the oppositeFilter paper was placed at the oppositeend of the cover slip to allow the iodineend of the cover slip to allow the iodine

solution to spread through epidermis.solution to spread through epidermis.

7.7.

A piece of filter paper are used toA piece of filter paper are used to

absorb the excess iodine solution.absorb the excess iodine solution.

8.8. The slide was observed throughThe slide was observed through

microscope.microscope.

9.9. The observation was drawed andThe observation was drawed andlabelled through a microscope.labelled through a microscope.


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ObservationsObservations


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Discussion:Discussion:


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chapter 3-plasma membrane

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