membrane structure
DESCRIPTION
Membrane Structure. ● The plasma membrane separates the living cell from its nonliving surroundings. Proteins. Outside of cell. Outside of cell. Hydrophilic region of protein. Hydrophilic head. Hydrophobic tail. Hydrophilic head. Phospholipid bilayer. Hydrophobic tail. - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Membrane Structure](https://reader036.vdocuments.mx/reader036/viewer/2022070421/56816294550346895dd30818/html5/thumbnails/1.jpg)
Membrane Structure● The plasma membrane separates the living cell from its nonliving surroundings.
(a) Phospholipid bilayer ofmembrane
(b) Fluid mosaic model ofmembrane
Outside of cell Outside of cellHydrophilicheadHydrophobictail
Hydrophilicregion ofprotein
Hydrophilichead
Hydrophobictail
Hydrophobicregions ofprotein
Phospholipidbilayer
Phospholipid
Proteins
Cytoplasm (inside of cell)
Cytoplasm (inside of cell)
![Page 2: Membrane Structure](https://reader036.vdocuments.mx/reader036/viewer/2022070421/56816294550346895dd30818/html5/thumbnails/2.jpg)
Membrane Structure
![Page 3: Membrane Structure](https://reader036.vdocuments.mx/reader036/viewer/2022070421/56816294550346895dd30818/html5/thumbnails/3.jpg)
Membrane Structure● Phospholipid structure
Phospholipids are amphipathic molecules
![Page 4: Membrane Structure](https://reader036.vdocuments.mx/reader036/viewer/2022070421/56816294550346895dd30818/html5/thumbnails/4.jpg)
Membrane Structure
![Page 5: Membrane Structure](https://reader036.vdocuments.mx/reader036/viewer/2022070421/56816294550346895dd30818/html5/thumbnails/5.jpg)
Membrane Models:
1935 Today
*Membranes are fluid
Membrane Structure
![Page 6: Membrane Structure](https://reader036.vdocuments.mx/reader036/viewer/2022070421/56816294550346895dd30818/html5/thumbnails/6.jpg)
Membranes are fluid
Membrane Structure
![Page 7: Membrane Structure](https://reader036.vdocuments.mx/reader036/viewer/2022070421/56816294550346895dd30818/html5/thumbnails/7.jpg)
Membrane Structure
Fibers ofextracellularmatrix
Cytoskeleton Cytoplasm
Attachment tocytoskeleton andextracellularmatrix
a
b Cell signaling
c
d
Enzymatic activity
Transport
e Intercellularjoining f Cell-cell
recognition
Cytoplasm
● Some functions of membrane proteins
● Cell surface – Extracellular Matrix
![Page 8: Membrane Structure](https://reader036.vdocuments.mx/reader036/viewer/2022070421/56816294550346895dd30818/html5/thumbnails/8.jpg)
Membrane Structure
![Page 9: Membrane Structure](https://reader036.vdocuments.mx/reader036/viewer/2022070421/56816294550346895dd30818/html5/thumbnails/9.jpg)
Membrane Transport
![Page 10: Membrane Structure](https://reader036.vdocuments.mx/reader036/viewer/2022070421/56816294550346895dd30818/html5/thumbnails/10.jpg)
Membrane Transport• Diffusion – a process in which molecules move from an
area of high concentration to an area of low concentration Molecules of dye Membrane
(a) Passive transport of one type of molecule
Net diffusion Net diffusion Equilibrium
![Page 11: Membrane Structure](https://reader036.vdocuments.mx/reader036/viewer/2022070421/56816294550346895dd30818/html5/thumbnails/11.jpg)
Membrane TransportAnimal cell
Plant cell
Normal
Flaccid (wilts)
Lysing
Turgid
Shriveled
Shriveled
Plasmamembrane
H2OH2O H2O H2O
H2OH2OH2O H2O
(a) Isotonicsolution
(b) Hypotonicsolution
(c) Hypertonicsolution
![Page 12: Membrane Structure](https://reader036.vdocuments.mx/reader036/viewer/2022070421/56816294550346895dd30818/html5/thumbnails/12.jpg)
Facilitated diffusion
Membrane Transport
![Page 13: Membrane Structure](https://reader036.vdocuments.mx/reader036/viewer/2022070421/56816294550346895dd30818/html5/thumbnails/13.jpg)
Membrane Transport–Active transport requires energy to move molecules across a membrane.
Lower solute concentration
Higher solute concentration
ATP
Solute
![Page 14: Membrane Structure](https://reader036.vdocuments.mx/reader036/viewer/2022070421/56816294550346895dd30818/html5/thumbnails/14.jpg)
*Active transport
Example: sodium-potassium pump
Membrane Transport
![Page 15: Membrane Structure](https://reader036.vdocuments.mx/reader036/viewer/2022070421/56816294550346895dd30818/html5/thumbnails/15.jpg)
Electrogenic pump:
*Some ion pumps generate voltage across membranes
*Voltage*Membrane potential
Membrane Transport
![Page 16: Membrane Structure](https://reader036.vdocuments.mx/reader036/viewer/2022070421/56816294550346895dd30818/html5/thumbnails/16.jpg)
*Each cell membrane has characteristic set of carrier proteins
Membrane Transport
![Page 17: Membrane Structure](https://reader036.vdocuments.mx/reader036/viewer/2022070421/56816294550346895dd30818/html5/thumbnails/17.jpg)
Passive Transport(requires no energy)
Active Transport(requires energy)
Diffusion Facilitated diffusion OsmosisHigher solute concentration
Lower solute concentration
Higher water concentration(lower solute concentration)
Lower water concentration(higher solute concentration)
Solute
Higher soluteconcentration
Lower soluteconcentration
ATP
Solu
te
Solu
te
Wat
er
Solu
te
MEMBRANE TRANSPORT
![Page 18: Membrane Structure](https://reader036.vdocuments.mx/reader036/viewer/2022070421/56816294550346895dd30818/html5/thumbnails/18.jpg)
Traffic of Large Molecules–Exocytosis is the secretion of large molecules within vesicles.
Outside of cell
Cytoplasm
Plasmamembrane
![Page 19: Membrane Structure](https://reader036.vdocuments.mx/reader036/viewer/2022070421/56816294550346895dd30818/html5/thumbnails/19.jpg)
Traffic of Large Molecules–Endocytosis takes material into a cell within vesicles that bud inward from the plasma membrane.
![Page 20: Membrane Structure](https://reader036.vdocuments.mx/reader036/viewer/2022070421/56816294550346895dd30818/html5/thumbnails/20.jpg)
*Phagocytosis
Exocytosis
*Pinocytosis
*Receptor-mediated endocytosis
Endocytosis
Transport of large moleculesTypes of endocytosis found in animal cells: