Membrane Transport Popad v2014

7/26/2019 Membrane Transport Popad v2014

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TRANSPORT THROUGH

CELL MEMBRANES

ByDr.M. Anthony David M.D

Professor Of Physiology

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Membrane Transport4


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At the end of this session YOU will be able to

List 2 reasons for cells to have commerce

Draw a concept map of membrane transport

List three important types of transport

Enumerate and contrast two types of activetransport

Give an example of active transport

List 3 types of vesicular transportEnumerate three features of transcytosis.


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Transport?

"o cell is an island.

#ells are self contained$ but intede!endent.

%o they need to &ive and ta'e(

)his commerce of import into the cell and exportfrom it is vital.

)his has to be throu&h the "ell #e#bane

)his helps the body fluids to maintain homeostasis.

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$h% i#!ot & e'!ot(

The !h%siolo)i"al f*n"tion of a "ell de!ends*!on+ N*tients,

O'%)en

$ate

The% #*st be -#!oted into the "ell.

Metaboli" waste !od*"ts #*st be e'!oted

o*t of the "ell.Me#bane Tans!ot s%ste#s e'ist to se/e

these two i#!otant f*n"tions

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BUL0 1LO$

)he pressure &radient ma'es the fluid flow fromhi&her to lower pressure re&ions.

-lood movin& in the intravascular compartment is

an example.n case of molecules and smaller particles$ transport

has to be more specific.

#ell membranes are selectively permeable or

semipermeable.

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MEMBRANE TRANSPORT SYSTEMS + TYPES

There are three types of transportacross the cell membrane:

I. Passive transport : No ATPneeded

II. Active transport : ATP needed

III. Vesicular transport

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TYPES O1 TRANSPORT13


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-. PASS-2E TRANSPORT

t is the mechanism of transport ofsubstances alon& the &radient withoutexpenditure of ener&y or 0)

t depends on

#oncentration &radient

Electrical &radientressure &radient

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SIMP! DI""#SIO$

)he net flux of the molecules from the area of hi&hconcentration to the area of low concentration.

Lipid soluble substances pass throu&h the cell

membrane easily.Examples 2$ "$ #2$ 0lcohol$ %teroid hormones and

wea' or&anic acids and bases water.

%odium and otassium pass throu&h the specificchannels

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S-MPLE 3-11US-ON1!


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Gatin) Me"hanis# in !otein "hannels

ccurs in #arrier mediated transport

)his controls the permeability

2olta)e Gated Channels )hese respondto the electrical potential across cellmembrane

Li)and Gated Channels these openwhen some other chemical substance bindswith &ated proteins

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1AC-L-TATE3 3-11US-ON

Glucose and 0mino acids pass throu&h Glucosetransporters and by amino acid transporters

)ypes of carrier protein systems5niport )he carrier proteins transport only one type

of molecules

%ymport or #otransport 6ere one substance islin'ed with another substance. E& Glucose is lin'ed

with the transport of %odium0ntiport or #ounter )ransport n this the carrier

proteins exchan&e one substance for another. E& "a787exchan&e or "a767ion exchan&e.

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"A%IITAT!D DI""#SIO$22


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"A%IITAT!D DI""#SIO$


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OSMOS-S

t is the diffusion of solvent$ throu&h ase#i!e#eable #e#bane from a solutioncontainin& low concentration towards the

solution containin& hi&her concentration ofsolutes.

Os#oti" !ess*e t is the minimum

pressure which when applied on the side ofhi&her solute concentration prevents theosmosis$ that is the net diffusion of water isprevented. E& #olloid smotic ressure.

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--. ACT-2E TRANSPORT

Expenditure of ener&y involved

0&ainst electrochemical &radient.

)ypes0. Pi#a% A"ti/e Tans!ot e& "a787

pump and #a77pump

-. Se"onda% A"ti/e Tans!ot E& 0lon&with "a7 the co transport of Glucose %GL) insmall intestine

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Na 0 ATPase3/


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Na 0 ATPase

ummary o ass ve c ve


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ummary o ass ve c veTransports

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ATIV! T"ANSP#"T33


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The thyroid $land accumulatesiodine

The iodine concentration can be

as much as % times moreconcentrated in the thyroid thanin blood.


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---. 2ES-CULAR TRANSPORT

)his is also an active transport. s ofthree types

0. E"D#9)%%-. E:#9)%%

#.);0"%#9)%%

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A. EN3OCYTOS-S

nvolves import of substances into cellss of two types 1. Pino"%tosis s cell drin'in&. )he process of

en&ulfin& li


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B. E4OCYTOS-S

t is the reverse of endocytosis

#alled as cell vomittin&

E& release of hormones$ en=ymes is byexocytosis

)he process of exocytosis re


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Endo & E'o"%tosis42


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RECEPTOR ME3-ATE3 EN3OCYTOS-S43


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C. TRANSCYTOS-S

s throu&h and throu&h transport

Endocytosis 7 Exocytosis

t has three sta&es>esicle formation

>esicle transportation

Doc'in& in the cell attachment withdoc'in& proteins.

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TRANSCYTOS-S4


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ULTRA1-LTRAT-ON

?iltration of all the solutes in theplasma into the interstitial fluid exceptthe proteins due to difference inhydrostatic pressures between bloodcapillary@3 mm 6&A and in theinterstitial space @1mm 6&A and in thecell@1mm 6&A

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Now YOU ae able to

List 2 reasons for cells to have commerceList Draw a concept map of membrane transport

List three important types of transport

Enumerate and contrast two types of activetransport

Give an example of active transport

List 3 types of vesicular transportEnumerate three features of transcytosis.

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Documents

Membrane Transport Popad v2014