membrane dynamics
DESCRIPTION
Membrane Dynamics. 5. About this Chapter. Mass balance and homeostasis Diffusion Protein-mediated, vesicular, and transepithelial transport Osmosis and tonicity The resting membrane potential Insulin secretion. Mass Balance in the Body. Figure 5-2. Mass Balance and Homeostasis. - PowerPoint PPT PresentationTRANSCRIPT
POWERPOINT® LECTURE SLIDE PRESENTATIONby LYNN CIALDELLA, MA, MBA, The University of Texas at Austin
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
HUMAN PHYSIOLOGYAN INTEGRATED APPROACH FOURTH EDITION
DEE UNGLAUB SILVERTHORN
UNIT 1UNIT 1
PART A
5Membrane Dynamics
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
About this Chapter
Mass balance and homeostasis
Diffusion
Protein-mediated, vesicular, and transepithelial transport
Osmosis and tonicity
The resting membrane potential
Insulin secretion
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Mass Balance in the Body
Figure 5-2
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Mass Balance and Homeostasis
Clearance Rate at which a molecule disappears from the body
Mass flow = concentration volume flow
Homeostasis equilibrium Osmotic equilibrium
Chemical disequilibrium
Electrical disequilibrium
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 5-3a
Homeostasis
Distribution of solutes in the body fluid compartments
The compartments in the body are in a state of chemical disequilibrium
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Homeostasis
Figure 5-3b
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 5-4
Diffusion
Map of membrane transport
Membranes are selectively permeable
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Diffusion: Seven Proprieties
Passive process
High concentration to low concentration
Net movement until concentration is equal
Rapid over short distances
Directly related to temperature
Inversely related to molecular size
In open system or across a partition
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 5-6
Simple Diffusion
Fick’s law of diffusion
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Membrane Proteins Function
Structural proteins
Enzymes
Membrane receptor proteins
Transporters Channel proteins
Carrier proteins
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 5-9a
Membrane Transport Proteins
Water channels and ion channels are examples of open channels
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 5-9b
Membrane Transport Proteins
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 5-11
Gating of Channel Proteins
Gated channels are either chemically gated or voltage-gated channels
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 5-12a
Types of Carrier-Mediated Transport
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 5-12b
Types of Carrier-Mediated Transport
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 5-12c
Types of Carrier-Mediated Transport
Carrier proteins never create a continuous passageway
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 5-15
Facilitated Diffusion
Diffusion of glucose into cell How is the concentration gradient maintained for
glucose?
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Mechanism of the Na+-K+-ATPase
ATP is used as an energy sourceFigure 5-17
Primary Active Transport
ICF
ECF
ADP
ATP
ATPase is phosphorylated
with Pi from ATP.Protein changesconformation.
Protein changesconformation.
P
PP
P
1
2
34
5
2 K+ releasedinto ICF
2 K+ fromECF bind
3 K+ releasedinto ICF
3 Na+ fromICF bind
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 5-17, step 1
Primary Active Transport
ICF
ECF1
3 Na+ fromICF bind
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 5-17, steps 1–2
Primary Active Transport
ICF
ECF
ADP
ATP
ATPase is phosphorylated
with Pi from ATP.
P
1
2
3 Na+ fromICF bind
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 5-17, steps 1–3
Primary Active Transport
ICF
ECF
ADP
ATP
ATPase is phosphorylated
with Pi from ATP.Protein changesconformation.
P
P
1
2
3 3 K+ releasedinto ICF
3 Na+ fromICF bind
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 5-17, steps 1–4
Primary Active Transport
PP
34 2 K+ fromECF bind
3 K+ releasedinto ICF
ICF
ECF
ADP
ATP
ATPase is phosphorylated
with Pi from ATP.Protein changesconformation.
P
1
2
3 Na+ fromICF bind
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 5-17, steps 1–5
Primary Active Transport
ICF
ECF
ADP
ATP
ATPase is phosphorylated
with Pi from ATP.Protein changesconformation.
Protein changesconformation.
P
PP
P
1
2
34
5
2 K+ releasedinto ICF
2 K+ fromECF bind
3 K+ releasedinto ICF
3 Na+ fromICF bind
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 5-18
Secondary Active Transport
Mechanism of the SGLT Transporter
Na+
Glu
Glu
Na+
Na+
Na+
[Na+] low[Glucose] high
[Na+] high[Glucose] low
SGLTprotein
Lumen ofintestineor kidney
Intracellular fluid Glucose bindingchanges carrier conformation.
Na+ released into cytosol. Glucose follows.
Na+ binding creates asite for glucose.
Na+ binds tocarrier.
Glu
Glu
1
2
3
4
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 5-18, step 1
Secondary Active Transport
Na+
Glu
[Na+] low[Glucose] high
[Na+] high[Glucose] low
SGLTprotein
Lumen ofintestineor kidney
Intracellular fluid
Na+ binds tocarrier.
1
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 5-18, steps 1–2
Secondary Active Transport
Na+
Glu
Glu
Na+
[Na+] low[Glucose] high
[Na+] high[Glucose] low
SGLTprotein
Lumen ofintestineor kidney
Intracellular fluid
Na+ binding creates asite for glucose.
Na+ binds tocarrier.
1
2
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Uses the energy of one molecule moving down its concentration gradient
Figure 5-18, steps 1–3
Secondary Active Transport
Na+
Glu
Glu
Na+
Na+
[Na+] low[Glucose] high
[Na+] high[Glucose] low
SGLTprotein
Lumen ofintestineor kidney
Intracellular fluid Glucose bindingchanges carrier conformation.
Na+ binding creates asite for glucose.
Na+ binds tocarrier.
Glu
1
2
3
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 5-18, steps 1–4
Secondary Active Transport
Na+
Glu
Glu
Na+
Na+
Na+
[Na+] low[Glucose] high
[Na+] high[Glucose] low
SGLTprotein
Lumen ofintestineor kidney
Intracellular fluid Glucose bindingchanges carrier conformation.
Na+ released into cytosol. Glucose follows.
Na+ binding creates asite for glucose.
Na+ binds tocarrier.
Glu
Glu
1
2
3
4