SlideShare a Scribd company logo
1 of 18
Transport across the plasma
        membrane




                              ALBIO9700/2006JK
Diffusion and facilitated diffusion
• Diffusion – the net movement of molecules (or ions) from a
  region of their higher concentration to a region of their lower
  concentration (molecules move down a concentration
  gradient)
• Molecules tend to reach an equilibrium where evenly spread
• The rate at which substance diffuses across a membrane
  depends on:
   – The ‘steepness’ of the concentration gradient. The greater
     the difference in concentration, the greater the difference in
     the number of molecules passing in the 2 directions and
     hence the faster the net rate of diffusion
   – Temperature. Diffusion takes place faster in high
     temperatures due to higher kinetic energy
   – The surface area. The greater the surface area, the more
     molecules or ions can cross it at any one moment (faster
     diffusion)
   – The nature of the molecules or ions. Substances with large
     molecules tend to diffuse more slowly. Non-polar molecules
     diffuse more easily through cell membranes as they are
     soluble in non-polar phospholipid tails
                                                              ALBIO9700/2006JK
ALBIO9700/2006JK
• Facilitated diffusion – diffusion of a
  substance through protein channels in a
  cell membrane
• The proteins provide hydrophilic areas
  that allow the molecules or ions to pass
  through a membrane that would otherwise
  be less permeable to them
• Rate depends on how many appropriate
  channels there are in the membrane and
  on whether they are open or not

                                      ALBIO9700/2006JK
ALBIO9700/2006JK
Active transport
• The energy-consuming transport of molecules or
  ions across a membrane against a concentration
  gradient made possible by transferring energy
  from respiration
• Like facilitated diffusion, active transport is
  achieved by special transport proteins, each of
  which is specific for a particular type of molecule
  or ion
• However, it requires energy (molecule ATP)
  because movement occurs up a concentration
  gradient
• Energy used to make the transport protein
  (carrier protein) change its 3D shape,
  transferring the molecules or ions across the
  membrane in the process
                                                ALBIO9700/2006JK
ALBIO9700/2006JK
Bulk transport
• Transport of large quantities of materials
  into cells (endocytosis) or out of cells
  (exocytosis)
• Exocytosis – process by which materials
  are removed from cells
• Endocytosis – engulfing of the material
  by the plasma membrane to form a small
  sac or ‘endocytotic vacuole’
  – Phagocytosis: bulk uptake of solid material
  – Pinocytosis: bulk uptake of liquid
                                              ALBIO9700/2006JK
Osmosis
• Solution = solute + solvent
• Partially permeable membrane – membrane
  which allows only certain molecules through
• If solution B has higher concentration of solute
  molecules than solution A – solution B is more
  concentrated than solution A/solution A is more
  dilute than solution B
• Osmosis involves net movement of water
  molecules only


                                             ALBIO9700/2006JK
ALBIO9700/2006JK
• Water potential and solute potential
  – Water potential: the tendency of water molecules
    to move from one place to another (psi, ψ)
  – Water always moves from a region of higher water
    potential to a region of lower water potential (down
    concentration gradient)
  – Osmosis: the movement of water molecules
    from a region of higher water potential to a
    region of lower water potential through a
    partially permeable membrane
  – Pure water has highest water potential (solutes lower
    the water potential)
  – Solute potential: the amount that the solute
    molecules lower the water potential of a solution.
    Always –ve (ψs).
                                                    ALBIO9700/2006JK
• Osmosis in animals
  – If the water potential of the solution surrounding the
    cell is too high, the cell swells and bursts
  – If it is too low, the cell shrinks
  – In animal cells ψ = ψs (water potential is equal to
    solute potential)
• Pressure potential
  – The greater the pressure applied, the greater the
    tendency for water molecules to be forced back
  – Increasing the pressure increases the water potential
  – Pressure potential: contribution made by pressure
    to water potential (ψp)
  – The pressure potential makes the water potential less
    negative and is therefore positive
                                                     ALBIO9700/2006JK
ALBIO9700/2006JK
• Osmosis in plant cells
  – Different from animal cells because of rigid
    and strong cell wall
  – Cell wall prevents the cell from bursting (lysis)
  – When fully inflated with water: turgid
  – Water potential is a combination of solute
    potential and pressure potential (ψ = ψs + ψp)
  – When protoplast shrinks and pulls away from
    the cell wall: plasmolysis
  – Incipient plasmolysis: the point at which
    pressure potential has just reached zero and
    plasmolysis is about to occur


                                                ALBIO9700/2006JK
ALBIO9700/2006JK
Exchange surfaces
• Gaseous exchange in
  mammalian lungs
  – Gaseous exchange
    surface: where
    oxygen from the
    external environment
    can diffuse into the
    body, and carbon
    dioxide can diffuse out
  – In humans: alveoli in
    the lungs

                              ALBIO9700/2006JK
• Uptake of mineral ions in a plant root
  – Specialised exchange surface: root hairs (very thin
    extensions of the cells that make up the outer layer
    or epidermis of a root)
  – Root hairs make contact with thin layer of water
    coating each soil particle and absorbs it by osmosis
  – Lower concentration of solutes in the water in the soil
    than there is inside the root hair cell
  – Water potential higher outside the root hair and
    water moves passively down the water potential
    gradient into the cells
  – Mineral ions also absorbed by facilitated diffusion if
    concentration is higher outside root hair
  – By active transport (carrier proteins and energy)
    when concentration is relatively low in soil
                                                     ALBIO9700/2006JK
ALBIO9700/2006JK

More Related Content

What's hot (20)

Cell and cellular transport system
Cell and cellular transport systemCell and cellular transport system
Cell and cellular transport system
 
Connective tissue
Connective tissue Connective tissue
Connective tissue
 
Cell organelles
Cell organellesCell organelles
Cell organelles
 
Vesicle transport
Vesicle transportVesicle transport
Vesicle transport
 
Plasma Membrane
Plasma MembranePlasma Membrane
Plasma Membrane
 
8 connective tissue
8 connective tissue8 connective tissue
8 connective tissue
 
Cell junctions
Cell junctionsCell junctions
Cell junctions
 
Cell & Types
Cell & TypesCell & Types
Cell & Types
 
Cell Structure
Cell StructureCell Structure
Cell Structure
 
Cells ppt.presentation
Cells ppt.presentationCells ppt.presentation
Cells ppt.presentation
 
Connective tissue
Connective tissueConnective tissue
Connective tissue
 
Cell Histology, Structure and Function of Cell,
Cell Histology, Structure and Function of Cell,Cell Histology, Structure and Function of Cell,
Cell Histology, Structure and Function of Cell,
 
Blood
BloodBlood
Blood
 
Histology -Epithelial tissue
Histology -Epithelial tissueHistology -Epithelial tissue
Histology -Epithelial tissue
 
Biology, cytoplasm
Biology, cytoplasmBiology, cytoplasm
Biology, cytoplasm
 
Structure & function of cell membrane
Structure & function of cell membraneStructure & function of cell membrane
Structure & function of cell membrane
 
Blood Histolgy
Blood HistolgyBlood Histolgy
Blood Histolgy
 
Structure of a Tissue,Functions and types of Tissue
Structure of a Tissue,Functions and types of TissueStructure of a Tissue,Functions and types of Tissue
Structure of a Tissue,Functions and types of Tissue
 
Plasma membrane, structure and function
Plasma membrane, structure and functionPlasma membrane, structure and function
Plasma membrane, structure and function
 
The cell membrane function
The cell membrane functionThe cell membrane function
The cell membrane function
 

Similar to Transport across plasma membrane

Transport and transport protein in cell biology
Transport and transport protein in cell biologyTransport and transport protein in cell biology
Transport and transport protein in cell biologyMangalore University
 
Cell membrane and Transport.pptx
Cell membrane and Transport.pptxCell membrane and Transport.pptx
Cell membrane and Transport.pptxdrn00r
 
transport_across_cell_membrane_cellular_transport.pptx
transport_across_cell_membrane_cellular_transport.pptxtransport_across_cell_membrane_cellular_transport.pptx
transport_across_cell_membrane_cellular_transport.pptxSanghamitraMohapatra5
 
membrane transport AIMC
membrane transport AIMCmembrane transport AIMC
membrane transport AIMCShamim Akram
 
diffusion and osmosis
diffusion and osmosisdiffusion and osmosis
diffusion and osmosisNafeesa Naeem
 
movement accross cell membrane
movement accross cell membranemovement accross cell membrane
movement accross cell membraneNoridah Yangman
 
Movement across membrane
Movement across membraneMovement across membrane
Movement across membraneguestb36f6cd
 
cell-membrane-lesson-ppt.pptx
cell-membrane-lesson-ppt.pptxcell-membrane-lesson-ppt.pptx
cell-membrane-lesson-ppt.pptxDevPanda5
 
cell-membrane-lesson-ppt (2)_organized (1).pdf
cell-membrane-lesson-ppt (2)_organized (1).pdfcell-membrane-lesson-ppt (2)_organized (1).pdf
cell-membrane-lesson-ppt (2)_organized (1).pdfenvironmentalgyan
 
Cell_Membrane_Transport.ppt
Cell_Membrane_Transport.pptCell_Membrane_Transport.ppt
Cell_Membrane_Transport.ppthaimn
 
Cell transportation combined
Cell transportation combinedCell transportation combined
Cell transportation combinedihmcbiology1213
 
Bio f4 chap_3_movement_of_substances_across_the_plasma_membrane
Bio f4 chap_3_movement_of_substances_across_the_plasma_membraneBio f4 chap_3_movement_of_substances_across_the_plasma_membrane
Bio f4 chap_3_movement_of_substances_across_the_plasma_membraneNorlina Abdul Aziz
 
Trasport across membrane cls
Trasport across membrane clsTrasport across membrane cls
Trasport across membrane clsAbhilashlucky1
 
ACTIVE AND PASSIVE TRANSPORT OF IONS.pptx
ACTIVE AND PASSIVE TRANSPORT OF IONS.pptxACTIVE AND PASSIVE TRANSPORT OF IONS.pptx
ACTIVE AND PASSIVE TRANSPORT OF IONS.pptxAliya Fathima Ilyas
 
Transport through Cell membrane 2023.pptx
Transport through Cell membrane 2023.pptxTransport through Cell membrane 2023.pptx
Transport through Cell membrane 2023.pptxKennyjrLMunisi
 
UNIT-I-cell transport.pptx
UNIT-I-cell transport.pptxUNIT-I-cell transport.pptx
UNIT-I-cell transport.pptxssuserb895a3
 

Similar to Transport across plasma membrane (20)

4 Cell membranes and transport
4 Cell membranes and transport4 Cell membranes and transport
4 Cell membranes and transport
 
005
005005
005
 
Diffusionrevision
DiffusionrevisionDiffusionrevision
Diffusionrevision
 
Diffusionrevision
DiffusionrevisionDiffusionrevision
Diffusionrevision
 
Transport and transport protein in cell biology
Transport and transport protein in cell biologyTransport and transport protein in cell biology
Transport and transport protein in cell biology
 
Cell membrane and Transport.pptx
Cell membrane and Transport.pptxCell membrane and Transport.pptx
Cell membrane and Transport.pptx
 
transport_across_cell_membrane_cellular_transport.pptx
transport_across_cell_membrane_cellular_transport.pptxtransport_across_cell_membrane_cellular_transport.pptx
transport_across_cell_membrane_cellular_transport.pptx
 
membrane transport AIMC
membrane transport AIMCmembrane transport AIMC
membrane transport AIMC
 
diffusion and osmosis
diffusion and osmosisdiffusion and osmosis
diffusion and osmosis
 
movement accross cell membrane
movement accross cell membranemovement accross cell membrane
movement accross cell membrane
 
Movement across membrane
Movement across membraneMovement across membrane
Movement across membrane
 
cell-membrane-lesson-ppt.pptx
cell-membrane-lesson-ppt.pptxcell-membrane-lesson-ppt.pptx
cell-membrane-lesson-ppt.pptx
 
cell-membrane-lesson-ppt (2)_organized (1).pdf
cell-membrane-lesson-ppt (2)_organized (1).pdfcell-membrane-lesson-ppt (2)_organized (1).pdf
cell-membrane-lesson-ppt (2)_organized (1).pdf
 
Cell_Membrane_Transport.ppt
Cell_Membrane_Transport.pptCell_Membrane_Transport.ppt
Cell_Membrane_Transport.ppt
 
Cell transportation combined
Cell transportation combinedCell transportation combined
Cell transportation combined
 
Bio f4 chap_3_movement_of_substances_across_the_plasma_membrane
Bio f4 chap_3_movement_of_substances_across_the_plasma_membraneBio f4 chap_3_movement_of_substances_across_the_plasma_membrane
Bio f4 chap_3_movement_of_substances_across_the_plasma_membrane
 
Trasport across membrane cls
Trasport across membrane clsTrasport across membrane cls
Trasport across membrane cls
 
ACTIVE AND PASSIVE TRANSPORT OF IONS.pptx
ACTIVE AND PASSIVE TRANSPORT OF IONS.pptxACTIVE AND PASSIVE TRANSPORT OF IONS.pptx
ACTIVE AND PASSIVE TRANSPORT OF IONS.pptx
 
Transport through Cell membrane 2023.pptx
Transport through Cell membrane 2023.pptxTransport through Cell membrane 2023.pptx
Transport through Cell membrane 2023.pptx
 
UNIT-I-cell transport.pptx
UNIT-I-cell transport.pptxUNIT-I-cell transport.pptx
UNIT-I-cell transport.pptx
 

More from Jaya Kumar

05 Cystic Fibrosis
05 Cystic Fibrosis05 Cystic Fibrosis
05 Cystic FibrosisJaya Kumar
 
03 Benefits and Hazards of Gene Technology
03 Benefits and Hazards of Gene Technology03 Benefits and Hazards of Gene Technology
03 Benefits and Hazards of Gene TechnologyJaya Kumar
 
02 Markers for Genetic Engineering
02 Markers for Genetic Engineering02 Markers for Genetic Engineering
02 Markers for Genetic EngineeringJaya Kumar
 
01 Gene Technology for Insulin Production
01 Gene Technology for Insulin Production01 Gene Technology for Insulin Production
01 Gene Technology for Insulin ProductionJaya Kumar
 
04 DNA Sequencing and Genetic Fingerprinting
04 DNA Sequencing and Genetic Fingerprinting04 DNA Sequencing and Genetic Fingerprinting
04 DNA Sequencing and Genetic FingerprintingJaya Kumar
 
03 Artificial Selection
03 Artificial Selection03 Artificial Selection
03 Artificial SelectionJaya Kumar
 
02 Species and Speciation
02 Species and Speciation02 Species and Speciation
02 Species and SpeciationJaya Kumar
 
01 selection and evolution
01 selection and evolution01 selection and evolution
01 selection and evolutionJaya Kumar
 
02 Passage of Info from Parent to Offspring
02 Passage of Info from Parent to Offspring02 Passage of Info from Parent to Offspring
02 Passage of Info from Parent to OffspringJaya Kumar
 
04 Phenotype Change Mutation and Environment
04 Phenotype Change Mutation and Environment04 Phenotype Change Mutation and Environment
04 Phenotype Change Mutation and EnvironmentJaya Kumar
 
03 The Chi Squared Test
03 The Chi Squared Test03 The Chi Squared Test
03 The Chi Squared TestJaya Kumar
 
Nervous Communication Microscope Slides
Nervous Communication Microscope SlidesNervous Communication Microscope Slides
Nervous Communication Microscope SlidesJaya Kumar
 
01 Importance of Homeostasis; Excretion; Control of Water
01 Importance of Homeostasis; Excretion; Control of Water01 Importance of Homeostasis; Excretion; Control of Water
01 Importance of Homeostasis; Excretion; Control of WaterJaya Kumar
 
03 Communication and Control in Flowering Plants
03 Communication and Control in Flowering Plants03 Communication and Control in Flowering Plants
03 Communication and Control in Flowering PlantsJaya Kumar
 
02 Nervous and Hormonal Communication
02 Nervous and Hormonal Communication02 Nervous and Hormonal Communication
02 Nervous and Hormonal CommunicationJaya Kumar
 
01 Classification
01 Classification01 Classification
01 ClassificationJaya Kumar
 
02 Conservation Issues
02 Conservation Issues02 Conservation Issues
02 Conservation IssuesJaya Kumar
 
Photosynthesis as an Energy Transfer Process
Photosynthesis as an Energy Transfer ProcessPhotosynthesis as an Energy Transfer Process
Photosynthesis as an Energy Transfer ProcessJaya Kumar
 
01 The need for Energy in Living Organisms
01 The need for Energy in Living Organisms01 The need for Energy in Living Organisms
01 The need for Energy in Living OrganismsJaya Kumar
 

More from Jaya Kumar (20)

05 Cystic Fibrosis
05 Cystic Fibrosis05 Cystic Fibrosis
05 Cystic Fibrosis
 
03 Benefits and Hazards of Gene Technology
03 Benefits and Hazards of Gene Technology03 Benefits and Hazards of Gene Technology
03 Benefits and Hazards of Gene Technology
 
02 Markers for Genetic Engineering
02 Markers for Genetic Engineering02 Markers for Genetic Engineering
02 Markers for Genetic Engineering
 
01 Gene Technology for Insulin Production
01 Gene Technology for Insulin Production01 Gene Technology for Insulin Production
01 Gene Technology for Insulin Production
 
04 DNA Sequencing and Genetic Fingerprinting
04 DNA Sequencing and Genetic Fingerprinting04 DNA Sequencing and Genetic Fingerprinting
04 DNA Sequencing and Genetic Fingerprinting
 
03 Artificial Selection
03 Artificial Selection03 Artificial Selection
03 Artificial Selection
 
02 Species and Speciation
02 Species and Speciation02 Species and Speciation
02 Species and Speciation
 
01 selection and evolution
01 selection and evolution01 selection and evolution
01 selection and evolution
 
02 Passage of Info from Parent to Offspring
02 Passage of Info from Parent to Offspring02 Passage of Info from Parent to Offspring
02 Passage of Info from Parent to Offspring
 
01 Meiosis
01 Meiosis01 Meiosis
01 Meiosis
 
04 Phenotype Change Mutation and Environment
04 Phenotype Change Mutation and Environment04 Phenotype Change Mutation and Environment
04 Phenotype Change Mutation and Environment
 
03 The Chi Squared Test
03 The Chi Squared Test03 The Chi Squared Test
03 The Chi Squared Test
 
Nervous Communication Microscope Slides
Nervous Communication Microscope SlidesNervous Communication Microscope Slides
Nervous Communication Microscope Slides
 
01 Importance of Homeostasis; Excretion; Control of Water
01 Importance of Homeostasis; Excretion; Control of Water01 Importance of Homeostasis; Excretion; Control of Water
01 Importance of Homeostasis; Excretion; Control of Water
 
03 Communication and Control in Flowering Plants
03 Communication and Control in Flowering Plants03 Communication and Control in Flowering Plants
03 Communication and Control in Flowering Plants
 
02 Nervous and Hormonal Communication
02 Nervous and Hormonal Communication02 Nervous and Hormonal Communication
02 Nervous and Hormonal Communication
 
01 Classification
01 Classification01 Classification
01 Classification
 
02 Conservation Issues
02 Conservation Issues02 Conservation Issues
02 Conservation Issues
 
Photosynthesis as an Energy Transfer Process
Photosynthesis as an Energy Transfer ProcessPhotosynthesis as an Energy Transfer Process
Photosynthesis as an Energy Transfer Process
 
01 The need for Energy in Living Organisms
01 The need for Energy in Living Organisms01 The need for Energy in Living Organisms
01 The need for Energy in Living Organisms
 

Recently uploaded

Full Stack Web Development Course for Beginners
Full Stack Web Development Course  for BeginnersFull Stack Web Development Course  for Beginners
Full Stack Web Development Course for BeginnersSabitha Banu
 
Inclusivity Essentials_ Creating Accessible Websites for Nonprofits .pdf
Inclusivity Essentials_ Creating Accessible Websites for Nonprofits .pdfInclusivity Essentials_ Creating Accessible Websites for Nonprofits .pdf
Inclusivity Essentials_ Creating Accessible Websites for Nonprofits .pdfTechSoup
 
Like-prefer-love -hate+verb+ing & silent letters & citizenship text.pdf
Like-prefer-love -hate+verb+ing & silent letters & citizenship text.pdfLike-prefer-love -hate+verb+ing & silent letters & citizenship text.pdf
Like-prefer-love -hate+verb+ing & silent letters & citizenship text.pdfMr Bounab Samir
 
INTRODUCTION TO CATHOLIC CHRISTOLOGY.pptx
INTRODUCTION TO CATHOLIC CHRISTOLOGY.pptxINTRODUCTION TO CATHOLIC CHRISTOLOGY.pptx
INTRODUCTION TO CATHOLIC CHRISTOLOGY.pptxHumphrey A Beña
 
GRADE 4 - SUMMATIVE TEST QUARTER 4 ALL SUBJECTS
GRADE 4 - SUMMATIVE TEST QUARTER 4 ALL SUBJECTSGRADE 4 - SUMMATIVE TEST QUARTER 4 ALL SUBJECTS
GRADE 4 - SUMMATIVE TEST QUARTER 4 ALL SUBJECTSJoshuaGantuangco2
 
AMERICAN LANGUAGE HUB_Level2_Student'sBook_Answerkey.pdf
AMERICAN LANGUAGE HUB_Level2_Student'sBook_Answerkey.pdfAMERICAN LANGUAGE HUB_Level2_Student'sBook_Answerkey.pdf
AMERICAN LANGUAGE HUB_Level2_Student'sBook_Answerkey.pdfphamnguyenenglishnb
 
How to Add Barcode on PDF Report in Odoo 17
How to Add Barcode on PDF Report in Odoo 17How to Add Barcode on PDF Report in Odoo 17
How to Add Barcode on PDF Report in Odoo 17Celine George
 
ENGLISH6-Q4-W3.pptxqurter our high choom
ENGLISH6-Q4-W3.pptxqurter our high choomENGLISH6-Q4-W3.pptxqurter our high choom
ENGLISH6-Q4-W3.pptxqurter our high choomnelietumpap1
 
DATA STRUCTURE AND ALGORITHM for beginners
DATA STRUCTURE AND ALGORITHM for beginnersDATA STRUCTURE AND ALGORITHM for beginners
DATA STRUCTURE AND ALGORITHM for beginnersSabitha Banu
 
call girls in Kamla Market (DELHI) 🔝 >༒9953330565🔝 genuine Escort Service 🔝✔️✔️
call girls in Kamla Market (DELHI) 🔝 >༒9953330565🔝 genuine Escort Service 🔝✔️✔️call girls in Kamla Market (DELHI) 🔝 >༒9953330565🔝 genuine Escort Service 🔝✔️✔️
call girls in Kamla Market (DELHI) 🔝 >༒9953330565🔝 genuine Escort Service 🔝✔️✔️9953056974 Low Rate Call Girls In Saket, Delhi NCR
 
HỌC TỐT TIẾNG ANH 11 THEO CHƯƠNG TRÌNH GLOBAL SUCCESS ĐÁP ÁN CHI TIẾT - CẢ NĂ...
HỌC TỐT TIẾNG ANH 11 THEO CHƯƠNG TRÌNH GLOBAL SUCCESS ĐÁP ÁN CHI TIẾT - CẢ NĂ...HỌC TỐT TIẾNG ANH 11 THEO CHƯƠNG TRÌNH GLOBAL SUCCESS ĐÁP ÁN CHI TIẾT - CẢ NĂ...
HỌC TỐT TIẾNG ANH 11 THEO CHƯƠNG TRÌNH GLOBAL SUCCESS ĐÁP ÁN CHI TIẾT - CẢ NĂ...Nguyen Thanh Tu Collection
 
Difference Between Search & Browse Methods in Odoo 17
Difference Between Search & Browse Methods in Odoo 17Difference Between Search & Browse Methods in Odoo 17
Difference Between Search & Browse Methods in Odoo 17Celine George
 
ECONOMIC CONTEXT - PAPER 1 Q3: NEWSPAPERS.pptx
ECONOMIC CONTEXT - PAPER 1 Q3: NEWSPAPERS.pptxECONOMIC CONTEXT - PAPER 1 Q3: NEWSPAPERS.pptx
ECONOMIC CONTEXT - PAPER 1 Q3: NEWSPAPERS.pptxiammrhaywood
 
MULTIDISCIPLINRY NATURE OF THE ENVIRONMENTAL STUDIES.pptx
MULTIDISCIPLINRY NATURE OF THE ENVIRONMENTAL STUDIES.pptxMULTIDISCIPLINRY NATURE OF THE ENVIRONMENTAL STUDIES.pptx
MULTIDISCIPLINRY NATURE OF THE ENVIRONMENTAL STUDIES.pptxAnupkumar Sharma
 
Grade 9 Q4-MELC1-Active and Passive Voice.pptx
Grade 9 Q4-MELC1-Active and Passive Voice.pptxGrade 9 Q4-MELC1-Active and Passive Voice.pptx
Grade 9 Q4-MELC1-Active and Passive Voice.pptxChelloAnnAsuncion2
 
Incoming and Outgoing Shipments in 3 STEPS Using Odoo 17
Incoming and Outgoing Shipments in 3 STEPS Using Odoo 17Incoming and Outgoing Shipments in 3 STEPS Using Odoo 17
Incoming and Outgoing Shipments in 3 STEPS Using Odoo 17Celine George
 

Recently uploaded (20)

Full Stack Web Development Course for Beginners
Full Stack Web Development Course  for BeginnersFull Stack Web Development Course  for Beginners
Full Stack Web Development Course for Beginners
 
Inclusivity Essentials_ Creating Accessible Websites for Nonprofits .pdf
Inclusivity Essentials_ Creating Accessible Websites for Nonprofits .pdfInclusivity Essentials_ Creating Accessible Websites for Nonprofits .pdf
Inclusivity Essentials_ Creating Accessible Websites for Nonprofits .pdf
 
Like-prefer-love -hate+verb+ing & silent letters & citizenship text.pdf
Like-prefer-love -hate+verb+ing & silent letters & citizenship text.pdfLike-prefer-love -hate+verb+ing & silent letters & citizenship text.pdf
Like-prefer-love -hate+verb+ing & silent letters & citizenship text.pdf
 
INTRODUCTION TO CATHOLIC CHRISTOLOGY.pptx
INTRODUCTION TO CATHOLIC CHRISTOLOGY.pptxINTRODUCTION TO CATHOLIC CHRISTOLOGY.pptx
INTRODUCTION TO CATHOLIC CHRISTOLOGY.pptx
 
GRADE 4 - SUMMATIVE TEST QUARTER 4 ALL SUBJECTS
GRADE 4 - SUMMATIVE TEST QUARTER 4 ALL SUBJECTSGRADE 4 - SUMMATIVE TEST QUARTER 4 ALL SUBJECTS
GRADE 4 - SUMMATIVE TEST QUARTER 4 ALL SUBJECTS
 
AMERICAN LANGUAGE HUB_Level2_Student'sBook_Answerkey.pdf
AMERICAN LANGUAGE HUB_Level2_Student'sBook_Answerkey.pdfAMERICAN LANGUAGE HUB_Level2_Student'sBook_Answerkey.pdf
AMERICAN LANGUAGE HUB_Level2_Student'sBook_Answerkey.pdf
 
How to Add Barcode on PDF Report in Odoo 17
How to Add Barcode on PDF Report in Odoo 17How to Add Barcode on PDF Report in Odoo 17
How to Add Barcode on PDF Report in Odoo 17
 
OS-operating systems- ch04 (Threads) ...
OS-operating systems- ch04 (Threads) ...OS-operating systems- ch04 (Threads) ...
OS-operating systems- ch04 (Threads) ...
 
ENGLISH6-Q4-W3.pptxqurter our high choom
ENGLISH6-Q4-W3.pptxqurter our high choomENGLISH6-Q4-W3.pptxqurter our high choom
ENGLISH6-Q4-W3.pptxqurter our high choom
 
DATA STRUCTURE AND ALGORITHM for beginners
DATA STRUCTURE AND ALGORITHM for beginnersDATA STRUCTURE AND ALGORITHM for beginners
DATA STRUCTURE AND ALGORITHM for beginners
 
call girls in Kamla Market (DELHI) 🔝 >༒9953330565🔝 genuine Escort Service 🔝✔️✔️
call girls in Kamla Market (DELHI) 🔝 >༒9953330565🔝 genuine Escort Service 🔝✔️✔️call girls in Kamla Market (DELHI) 🔝 >༒9953330565🔝 genuine Escort Service 🔝✔️✔️
call girls in Kamla Market (DELHI) 🔝 >༒9953330565🔝 genuine Escort Service 🔝✔️✔️
 
HỌC TỐT TIẾNG ANH 11 THEO CHƯƠNG TRÌNH GLOBAL SUCCESS ĐÁP ÁN CHI TIẾT - CẢ NĂ...
HỌC TỐT TIẾNG ANH 11 THEO CHƯƠNG TRÌNH GLOBAL SUCCESS ĐÁP ÁN CHI TIẾT - CẢ NĂ...HỌC TỐT TIẾNG ANH 11 THEO CHƯƠNG TRÌNH GLOBAL SUCCESS ĐÁP ÁN CHI TIẾT - CẢ NĂ...
HỌC TỐT TIẾNG ANH 11 THEO CHƯƠNG TRÌNH GLOBAL SUCCESS ĐÁP ÁN CHI TIẾT - CẢ NĂ...
 
Difference Between Search & Browse Methods in Odoo 17
Difference Between Search & Browse Methods in Odoo 17Difference Between Search & Browse Methods in Odoo 17
Difference Between Search & Browse Methods in Odoo 17
 
Raw materials used in Herbal Cosmetics.pptx
Raw materials used in Herbal Cosmetics.pptxRaw materials used in Herbal Cosmetics.pptx
Raw materials used in Herbal Cosmetics.pptx
 
ECONOMIC CONTEXT - PAPER 1 Q3: NEWSPAPERS.pptx
ECONOMIC CONTEXT - PAPER 1 Q3: NEWSPAPERS.pptxECONOMIC CONTEXT - PAPER 1 Q3: NEWSPAPERS.pptx
ECONOMIC CONTEXT - PAPER 1 Q3: NEWSPAPERS.pptx
 
TataKelola dan KamSiber Kecerdasan Buatan v022.pdf
TataKelola dan KamSiber Kecerdasan Buatan v022.pdfTataKelola dan KamSiber Kecerdasan Buatan v022.pdf
TataKelola dan KamSiber Kecerdasan Buatan v022.pdf
 
MULTIDISCIPLINRY NATURE OF THE ENVIRONMENTAL STUDIES.pptx
MULTIDISCIPLINRY NATURE OF THE ENVIRONMENTAL STUDIES.pptxMULTIDISCIPLINRY NATURE OF THE ENVIRONMENTAL STUDIES.pptx
MULTIDISCIPLINRY NATURE OF THE ENVIRONMENTAL STUDIES.pptx
 
LEFT_ON_C'N_ PRELIMS_EL_DORADO_2024.pptx
LEFT_ON_C'N_ PRELIMS_EL_DORADO_2024.pptxLEFT_ON_C'N_ PRELIMS_EL_DORADO_2024.pptx
LEFT_ON_C'N_ PRELIMS_EL_DORADO_2024.pptx
 
Grade 9 Q4-MELC1-Active and Passive Voice.pptx
Grade 9 Q4-MELC1-Active and Passive Voice.pptxGrade 9 Q4-MELC1-Active and Passive Voice.pptx
Grade 9 Q4-MELC1-Active and Passive Voice.pptx
 
Incoming and Outgoing Shipments in 3 STEPS Using Odoo 17
Incoming and Outgoing Shipments in 3 STEPS Using Odoo 17Incoming and Outgoing Shipments in 3 STEPS Using Odoo 17
Incoming and Outgoing Shipments in 3 STEPS Using Odoo 17
 

Transport across plasma membrane

  • 1. Transport across the plasma membrane ALBIO9700/2006JK
  • 2. Diffusion and facilitated diffusion • Diffusion – the net movement of molecules (or ions) from a region of their higher concentration to a region of their lower concentration (molecules move down a concentration gradient) • Molecules tend to reach an equilibrium where evenly spread • The rate at which substance diffuses across a membrane depends on: – The ‘steepness’ of the concentration gradient. The greater the difference in concentration, the greater the difference in the number of molecules passing in the 2 directions and hence the faster the net rate of diffusion – Temperature. Diffusion takes place faster in high temperatures due to higher kinetic energy – The surface area. The greater the surface area, the more molecules or ions can cross it at any one moment (faster diffusion) – The nature of the molecules or ions. Substances with large molecules tend to diffuse more slowly. Non-polar molecules diffuse more easily through cell membranes as they are soluble in non-polar phospholipid tails ALBIO9700/2006JK
  • 4. • Facilitated diffusion – diffusion of a substance through protein channels in a cell membrane • The proteins provide hydrophilic areas that allow the molecules or ions to pass through a membrane that would otherwise be less permeable to them • Rate depends on how many appropriate channels there are in the membrane and on whether they are open or not ALBIO9700/2006JK
  • 6. Active transport • The energy-consuming transport of molecules or ions across a membrane against a concentration gradient made possible by transferring energy from respiration • Like facilitated diffusion, active transport is achieved by special transport proteins, each of which is specific for a particular type of molecule or ion • However, it requires energy (molecule ATP) because movement occurs up a concentration gradient • Energy used to make the transport protein (carrier protein) change its 3D shape, transferring the molecules or ions across the membrane in the process ALBIO9700/2006JK
  • 8. Bulk transport • Transport of large quantities of materials into cells (endocytosis) or out of cells (exocytosis) • Exocytosis – process by which materials are removed from cells • Endocytosis – engulfing of the material by the plasma membrane to form a small sac or ‘endocytotic vacuole’ – Phagocytosis: bulk uptake of solid material – Pinocytosis: bulk uptake of liquid ALBIO9700/2006JK
  • 9. Osmosis • Solution = solute + solvent • Partially permeable membrane – membrane which allows only certain molecules through • If solution B has higher concentration of solute molecules than solution A – solution B is more concentrated than solution A/solution A is more dilute than solution B • Osmosis involves net movement of water molecules only ALBIO9700/2006JK
  • 11. • Water potential and solute potential – Water potential: the tendency of water molecules to move from one place to another (psi, ψ) – Water always moves from a region of higher water potential to a region of lower water potential (down concentration gradient) – Osmosis: the movement of water molecules from a region of higher water potential to a region of lower water potential through a partially permeable membrane – Pure water has highest water potential (solutes lower the water potential) – Solute potential: the amount that the solute molecules lower the water potential of a solution. Always –ve (ψs). ALBIO9700/2006JK
  • 12. • Osmosis in animals – If the water potential of the solution surrounding the cell is too high, the cell swells and bursts – If it is too low, the cell shrinks – In animal cells ψ = ψs (water potential is equal to solute potential) • Pressure potential – The greater the pressure applied, the greater the tendency for water molecules to be forced back – Increasing the pressure increases the water potential – Pressure potential: contribution made by pressure to water potential (ψp) – The pressure potential makes the water potential less negative and is therefore positive ALBIO9700/2006JK
  • 14. • Osmosis in plant cells – Different from animal cells because of rigid and strong cell wall – Cell wall prevents the cell from bursting (lysis) – When fully inflated with water: turgid – Water potential is a combination of solute potential and pressure potential (ψ = ψs + ψp) – When protoplast shrinks and pulls away from the cell wall: plasmolysis – Incipient plasmolysis: the point at which pressure potential has just reached zero and plasmolysis is about to occur ALBIO9700/2006JK
  • 16. Exchange surfaces • Gaseous exchange in mammalian lungs – Gaseous exchange surface: where oxygen from the external environment can diffuse into the body, and carbon dioxide can diffuse out – In humans: alveoli in the lungs ALBIO9700/2006JK
  • 17. • Uptake of mineral ions in a plant root – Specialised exchange surface: root hairs (very thin extensions of the cells that make up the outer layer or epidermis of a root) – Root hairs make contact with thin layer of water coating each soil particle and absorbs it by osmosis – Lower concentration of solutes in the water in the soil than there is inside the root hair cell – Water potential higher outside the root hair and water moves passively down the water potential gradient into the cells – Mineral ions also absorbed by facilitated diffusion if concentration is higher outside root hair – By active transport (carrier proteins and energy) when concentration is relatively low in soil ALBIO9700/2006JK