Date post: | 20-Feb-2017 |
Category: |
Science |
Upload: | universidad-del-sagrado-corazon |
View: | 533 times |
Download: | 8 times |
BIO111
Membrana y transporte celular
Figureage 97
Cell interior
Plasma membranePlasma membrane
Outside cell 0.1 µm
Hydrophilic heads
Hydrophobic tails
(a) Phospholipids in water (b) Detergent in water
Figure 5-7Page 100
E-face
P-face
Cytosol
Extracellularfluid
E-face
P-face
(a)
(b)
Movimiento de fosfolípidos
Time
Glycoprotein
Hydrophilichelixa
Cholesterol
Carbohydratechain
Extracellular fluid
HydrophilicHydrophobic
CytosolPeripheral
protein
Carbohydratechains
Integralproteins
Glycolipid
Funciones de las proteínas de la membrana
AnclajeTransporte pasivoTransporte activoActividad enzimáticaComunicaciónReconocimientoUnión
OutsidecellOutsidecell
Insidecell
Integrin
Outsidecell
Outsidecell
Outsidecell
Insidecell
Insidecell
Insidecell
ATP
ADPP
Na+
(a) Anchoring (b) Passive transport
(d) Enzymatic activity(c) Active transport
Outsidecell
Insidecell
Outsidecell 1
Insidecell 2
Outsidecell
Insidebacterial
cell
HumanBcell
HumanBcell
Antigen
(e) Signal transduction (f) Cell recognition
(g) Intercellular junction
(g) Intercellular junction
Mecanismos de transporte celular
Difusión OsmósisDifusión facilitadaTransporte activoEndocitosisExocitosis
Difusión
1 2 3
Osmosis
Diferencia en concentración
Membrana selectiva
Presión osmótica
Figure 5-11Page 104
Net movementof water molecules
Pressure applied to piston to resist upward movement
Waterplussolute
Pure water
Watermolecule
Moleculeof solute
Selectivelypermeablemembrane
Solución isotónica
Solución hipertónica
Solución hipotónica
Outsidecell
Outsidecell
Outsidecell
Insidecell
Insidecell
Insidecell
No net watermovement
Net water movementout of the cell
Net water movementinto the cell
Isotonic solution Hypertonic solution Hypotonic solution
10µm
(a)
(b)
(c)
Figure 5-13Page 106
Plasmamembrane
Vacuole
Vacuolarmembrane(tonoplast)
CytoplasmPlasmamembrane
Vacuole
Nucleus(a) (b) (c)
Plasmólisis
Turgencia
Transporte activo
aPage 108
Higher
Higher
Lower
Lower
Outsidecell
Cytosol
Activetransportchannel
ATP
Sodi
umco
ncen
trati
on g
radi
ent
Pota
ssiu
mco
ncen
trati
on g
radi
ent
(a)
Outside cell Outside cell
Inside cell Inside cell
Lowconcentration
of solute
Highconcentration
of solute
Figure 5-15bPage 108
ATP
ADP
1. Three sodium ions bindto the transport protein
2. A phosphate group istransferred from ATP tothe transport protein
3. The transport protein under-goes a conformationalchange, releasing threesodium ions outside the cell.
6. The transport proteinreturns to its original shape:Two potassium ions arereleased inside the cell
5. The phosphate is released
4. Two potassium ions bindto the transport protein
(b)
Endocitosis
Figure 5-17Page 110
0.25µm
1. A vesicle approaches the plasma membrane
2. fuses with it and
3. releases its contents outside the cell.
Figure 5-18(1)Page 111
3. Lysosomes may fuse with the vacuoleand pour their potent enzymes onto theingested material.
2. The vacuole then pinches off inside thecell.
1. Folds of the plasma membrane surroundthe particle to be ingested, forming asmall vacuole around it.
Figure 5-18(2)Page 111
Nucleus
Lysosomes Large vacuole
Bacteria
Ingested bacteria
Glycogen (storednutrients)
2.5µ
m
Figure 5-19Page 111
Microvilli Pinocytotic vesicle
Cytosol
Figure 5-20aPage 112
Plasmamembrane
Cytosol
Uncoatedvesicle
Endosome
LDL receptor transportedto plasma membraneand recycled
Freecholesterol
Secondarylysosome
LysosomeClathrin
Clathrinrecycled
Coatedpit
LDLparticle
LDLreceptor
(a)
Figure 5-20bPage 112
0.25µm(b)
Fig. 5-23a, p. 126
Coatedpit
LDL attaches to specificreceptors in coated pitson plasma membrane.
Vesicle containing LDLparticles fuses with alysosome, forming asecondary lysosome.Hydrolytic enzymesthen digest cholesterolfrom LDL particles foruse by cell.
Endocytosis results information of a coatedvesicle in cytosol.Seconds latercoat is removed.
Uncoated vesiclefuses with endosome.
Receptors are returnedto plasma membraneand recycled.
(a) Uptake of low-density lipoprotein (LDL) particles, which transport cholesterol in the blood.
Endosome
Endosome
Primary lysosome
Clathrinrecycled
Secondarylysosome
Freecholesterol
Clathrin
Cytosol
Uncoatedvesicle
Plasmamembrane
LDLreceptor
LDLparticle
1
2
3
4
5
1
2
3
4
5
Exocitosis
Fig. 5-20, p. 124
Exocitosis
Ciclo Celular
Fig. 10-5, p. 215
INTERPHASE
G1 (First gap phase)
S (Synthesis phase)
G2 (Second gap
phase)
M PHASE (Mitosis and cytokinesis)
Fig. 10-6a, p. 216
Fig. 10-6b, p. 217