Histo Lec 1 Tissue Prep & Cyto

8/16/2019 Histo Lec 1 Tissue Prep & Cyto

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Histology


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• Please come on time.• You may have your snacks/breakfast and

non-alcoholic beverages with you.• Please be considerate with the volume of

your ringtones and message alerts.

• You don’t have to take down notes – a copy of the lecture will be provided

after class•

Sources – !olor "tlas of Histology #th edition $%&'() – *un+uiera’s ,asic Histology 'th edition $%&') – diiore’s "tlas of Histology ''th edition $%&&)


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• %& item +ui0 will be given aftereach lecture – this is a way for you to have the chance to

improve your grades and pass the sub1ectwithout taking too much of your time since itwill be given after the lecture

• 23am items may ask +uestions fromprevious lectures – repetition is one way to improve your memory


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Histology and

4ethods of Study


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• Sources – !olor "tlas of Histology by 5artner and Hiatt #th

edition $%&'() –

*un+uiera’s ,asic Histology by 4escher 'th edition $%&') – diiore’s "tlas of Histology by 2roschenko ''th

edition $%&&)


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6ecture 7utline

• PREPARATION OF TISSUES FOR STUDY

– i3ation8 2mbedding 9 Sectioning8 Staining• LIGHT MICROSCOPY

– ,right-ield 4icroscopy8 luorescence 4icroscopy8

Phase-!ontrast 4icroscopy8 !onfocal 4icroscopy8Polari0ing 4icroscopy

• ELECTRON MICROSCOPY

– :ransmission electron 4icroscopy8 Scanning electron4icroscopy

• AUTORADIOGRAPHY

• CELL & TISSUE CULTURE

• ENZYME HISTOCHEMISTRY

• VISUALIZING SPECIFIC MOLECULES

– ;mmunohistochemistry8 Hybridi0ation :echni+ues


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6ecture 7utline

• PREPARATION OF TISSUES FOR STUDY

– i3ation8 2mbedding 9 Sectioning8Staining

•

LIGHT MICROSCOPY – ,right-ield 4icroscopy8 luorescence 4icroscopy8 Phase-!ontrast

4icroscopy8 !onfocal 4icroscopy8 Polari0ing 4icroscopy• ELECTRON MICROSCOPY

– :ransmission electron 4icroscopy8 Scanning electron 4icroscopy• AUTORADIOGRAPHY

• CELL & TISSUE CULTURE• INTERPRETATION OF STRUCTURES IN TISSUE SECTIONS


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Histology

• study of the tissues of the body and howtissues are arranged to constitute organs

• involves all aspects of tissue biology8

focuses on how cells’ structure andarrangement optimi0e functions speci


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% interacting componentscells and e3tracellular matri3 $2!4)

• 2!4 – consists of macromolecules8 most of which form comple3

structures8 such as collagen


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PREPARATION OF TISSUES FORSTUDY

• most commo !"oc#$%"# used in histologicresearch !"#!"tio o' tiss%# s#ctios o"slic#s that can be studied with the lightmicroscope

• • :he ideal microscopic preparation

– Preserved tissue on the slide has the same structureand molecular composition as it had in the body

- However8 seldom feasible8 due to artifacts8distortions8 and loss of components due to thepreparation


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Steps for :issue Preparation


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St#!s

• i3ation• >ehydration

• !learing• ;ne’

!;2:?i3 the seat@ A7: >2!(E-I- :


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4icrotome


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4icrotome

• used for sectioning paraBn-embeddedtissues for light microscopy

• trimmed tissue is mounted in the paraBn

block holder turn the drive wheel tissue advances a controlled distance $C1– 10 μm) tissue block passes over thesteel knife edge section is cut at a

thickness e+ual to the distance the blockadvanced paraBn sections are placedon glass slides and processed


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4icrotome

• or :24 sections less than 1 μmthick are prepared from resin-embedded cells using an

ultramicrotome with a glass ordiamond knife.


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Step by Step Fi)tio

• P%"!os#* :o avoid tissue digestion byen0ymes present within the cells $autolysis)or bacteria and to preserve cell and tissue

structure• P"oc#ss* immersion in solutions of

stabili0ing or cross-linking compounds calledxatives

• :issues are cut into small fragments before


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Step by Step Fi)tio

• Fo"mli – widely used for light microscopy – a buDered isotonic solution of !"

formaldehyde – ,oth formaldehyde and glutaraldehyde8 a


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;n a nutshell

• Fi)tio* – Small pieces of tissue are placed in

solutions of chemicals that #reserve by

crosslinking #roteins and inactivatingdegradative en*ymes.


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Step by step D#+y$"tio

• P%"!os#* H%& is e3tracted from the


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Step by step Cl#"ig

• P%"!os#* Solvent in


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Step by step I,lt"tio

• P%"!os#* :o evaporate the organicsolvent and allow tissue to harden

• P"oc#ss* :he fully cleared tissue isplaced in melted paraBn in an ovenat +',)-0,. to eva#orate the clearingsolvent and the tissue is


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Step by step Em-#$$ig

• P%"!os#* :issues are embedded in asolid medium to impart a solidconsistency to facilitate sectioning.

• P"oc#ss* 2mbedding materials – paraBn - routinely for light microscopyG – resins - both light and electron

microscopy.


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Step by step T"immig & S#ctioig

• P%"!os#* :o e3pose tissue and preparefor cutting

• P"oc#ss* :issue is placed on microtome

and cut

Spatial units commonly used in histology•

' m I '/'&&& of a mm or '&-# m• ' nm I &.&&' m I '&-# mm I '&-J m)• angstrom $' K I &.' nm or '&-( m)


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or :24

• :issues to be embedded with plastic resinare also dehydrated in ethanol subse+uently inltrated with #lastic solvents

replaced by plastic solutions that hardenwith the addition of cross-linkingpolymeri0ers hardened block $tissue andparaBn) placed in microtome and sliced at

1)10 μm $steel blade( thickness or even /1 μm $glass or diamond knives ofultramicrotomes) for electron microscopy


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• :he whole procedure8 from


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MEDICAL APPLICATION

• 7L biopsies are


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Stiig

• 4ost cells and e3tracellular material arecompletely colorless

• :o be studied microscopically sections must

typically be stained $dyed) to permitdistinctions between tissue components

• >yes are selective - behave like acidic orbasic compounds and forming electrostatic$salt) linkages with ioni0able radicals ofmolecules in tissue


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Stiig

• !ell components such as nucleic acids with a netnegative charge $anionic( stain more readily withbasic dyes $baso#hilic(

• :he main tissue components that ioni0e and reactwith basic dyes do so because of acids in theircomposition $%23 4%23 and glycosaminoglycans)

• 2g. toluidine blue8 alcian blue8 and methylene

blue• Hemato3ylin behaves like a basic dye8 staining

basophilic tissue components


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Stiig

• .ationic components8 such as proteinswith many ioni0ed amino groups haveaBnity for acidic dyes $acido#hilic)

• "cid dyes $eg8 eosin8 orange 58 andacid fuchsin) stain the acidophilic

components of tissues such asmitochondria3 secretory granules3 andcollagen


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Staining H#mto)yli $Eosi

• 4ost commonly used• &ematoxylin produces a dark blue or #ur#le color8 staining %2 in the cell

nucleus and other acidic structures$such as LA"-rich portions of thecytoplasm and the matri3 of cartilage)

• 5osin stains other cyto#lasmiccom#onents and collagen #ink .


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H92 staining small intestine basophilic cell nuclei IpurpleG

cytoplasm I pink.


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Staining T"ic+"om#s

• >yes such as the trichromes $eg84allory stain8 4asson stain) are usedin more comple3 histologic

procedures.

• :he trichromes show the nuclei and

cytoplasm and help to distinguishe3tracellular tissue components betterthan H92.


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Staining P#"io$ic Aci$(Sc+i/ 0PAS1

• Msed to identify >A" in nuclei usingthe 6eulgen reaction7 deo3yribosesugars are hydroly0ed by mild

hydrochloric acid then treated withP"S.

• transformation of 13')glycol grou#s present in the sugars into aldehyderesidues react with SchiD reagent

#ur#le or magenta color


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P"S $small intestine) staining is most intense at the lumen where pro1ecting microvilli have aprominent layer of glyco#roteins at the lumen $6) and in the mucin-rich secretory granulesof goblet cells due to high content of oligosaccharides and polysaccharides respectively.

P"S stained tissue was counterstained with hemato3ylin to show the cell nuclei.


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Staining Co%t#"sti

• a single stain that is appliedseparately to allow better recognitionof nuclei and other structures

• ;n H92 staining8 eosin is thecounterstain to hemato3ylin.


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Staining Li!i$s

• Sudan black – 6ipid-rich st3 best revealed with lipid-

soluble dyes –

"void processing steps that removelipids -- heat8 organic solvents8 orparaBn.

• ro0en sections are stained in alcohol sol’n

saturated with li#o#hilic dye $eg. Sudan black)8which dissolves in lipid-rich structures of cells.

8lack “sud)an” richin fats


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I2m 3tc+ig yo%4


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6ecture 7utline• PREPARATION OF TISSUES FOR STUDY

– i3ation8 2mbedding 9 Sectioning8 Staining

• LIGHT MICROSCOPY

– ,right-ield 4icroscopy8 luorescence

4icroscopy8 Phase-!ontrast 4icroscopy8!onfocal 4icroscopy8 Polari0ing4icroscopy

• ELECTRON MICROSCOPY

– :ransmission electron 4icroscopy8 Scanning electron 4icroscopy• AUTORADIOGRAPHY


• INTERPRETATION OF STRUCTURES IN TISSUE SECTIONS


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LIGHT MICROSCOPY

• !onventional bright-


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5"ig+t(Fi#l$ Mic"osco!y

• Stained preparations are e3aminedby means of ordinary light thatpasses through the specimen

• 4icroscope includes an opticalsystem and mechanisms to move

and focus the specimen


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• 7ptical components three lenses

–Condenser collects and focuses a coneof light that illuminates the tissue slideon the stage.


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• 7ptical components three lenses

• 9b:ective lens enlarge and pro1ect theilluminated image of the ob:ect toward theeyepiece.

• ;nterchangeable ob1ectives with diDerentmagni


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• 7ptical components three lenses – ' 5ye#ieces or ocular lens further

magni


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• :he total magni


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R#sol6ig Po3#"

• critical factor for a +uality image - clarity and richness ofdetail

• de


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Fl%o"#sc#c# Mic"osco!y

• hen certain cellular substances are irradiatedby light of a proper wavelength8 they emit lightwith a longer wavelengthQa phenomenon called7%o"#sc#c#8

• Fl%o"#sc#c# mic"osco!y* tissue sections areirradiated with ultraviolet $MR) light and theemission is in the visible portion of the spectrum.

• :he =uorescent substances appear brilliant on adark background.


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• luorescent compounds with aBnityfor speci


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"cridine orange binds nucleic acids and causes >A" in cell nuclei $N1to emit y#llo3 lig+t and the LA"-rich cytoplasm $R1 to appearo"g# in these cells of a kidney tubule


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• luorescent compounds with aBnityfor speci"P; and Hoechst stain - speciA" and are used to stain cell

nuclei8 emitting a characteristic blue =uorescence under MR.


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!ultured cells stained with >"P; $(8 #-diamino-%-phenylindole) thatbinds >A" and with =uorescein-phalloidin that binds actin


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P+s#(Cot"st Mic"osco!y

• Mnstained cells and tissue sections8 whichare usually trans#arent and colorless

•

!ellular detail diBcult to see in unstainedtissues because all parts of the specimenhave roughly similar optical densities

• Mses a lens system that produces visibleimages from transparent ob1ects and can beused with living8 cultures cells


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Phase !ontrast 4icroscopy

$a),right-


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Co'ocl Mic"osco!y

• !onfocal microscopy avoids strayingof light to enhance the contrast ofimages and improve resolving power

of the ob1ective lens


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Pol"i.ig Mic"osco!y

• "llows the recognition of stained orunstained structures made of highlyorgani0ed subunits.

• 8irefringence8 the ability to rotate thedirection of vibration of polari0ed light8 is afeature of crystalline substances or

substances containing highly orientedmolecules8 such as cellulose8 collagen8microtubules8 and actin


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hat I see in the Microscope

in my Histology Class


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– ,right-ield 4icroscopy8 luorescence 4icroscopy8 Phase-!ontrast 4icroscopy8 !onfocal 4icroscopy8 Polari0ing

4icroscopy• ELECTRON MICROSCOPY

– :ransmission electron 4icroscopy8 – Scanning electron 4icroscopy

• AUTORADIOGRAPHY




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ELECTRON MICROSCOPY

• :ransmission and scanning electronmicroscopes are based on theinteraction of tissue com#onents with

beams of electrons.

• :he wavelength in the electron beam

is much shorter than that of light8allowing a 1000)fold increase inresolution.

T i i El t


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T"smissio El#ct"oMic"osco!y

• :24 is an imaging system that permits resolutionaround nm – high resolution allows magni


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• :24 re+uires very thin sections $


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C"yo'"ct%"# $ F"##.#Etc+ig

• allow :24 study of cells without


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Scig #l#ct"o mic"osco!y0SEM1

• High resolution view of the surfaces of cells8 tissues• 6ike :24 focuses a very narrow beam of electrons• Mnlike :24 beam does not pass through the specimen

•

Specimen surface is dried 9 spray-coated with heavy metal $gold)• ,eam is scanned8 it interacts with the metal atoms and produces

re=ected electrons or secondary electrons emitted from the metal.• :hese are captured by a detector8 and the resulting signal is

processed to produce a black-and-white image on a monitor.• 2asy to interpret because they present a > view that appears to be

illuminated from above


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• AUTORADIOGRAPHY • CELL & TISSUE CULTURE



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AUTORADIOGRAPHY

• method of locali*ing newly synthesi*edmacromolecules $>A"8 LA"8 !H7A8 glyco!H7A8polysaccharides) in cells or tissue sections.

• 4adioactively labeled metabolites $nucleotides8

amino acids8 sugars) incorporated into themacromolecules emit weak radiation• Slides are developed photographically.• Silver bromide crystals reduced by the radiation

produce small black grains of metallic silver8 whichunder either the light microscope or :24 indicate thelocations of radiolabeled macromolecules in thetissue


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• AUTORADIOGRAPHY

• CELL & TISSUE CULTURE• INTERPRETATION OF STRUCTURES IN TISSUE SECTIONS


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CELL & TISSUE CULTURE

• in vitro - 6ive cells and tissuesmaintained and studied outside thebody in culture

• in vivo - >n the organism8 cells arebathed in =uid derived from blood

plasma8 containing many diDerentmolecules re+uired for survival andgrowth

MEDICAL APPLICATION* !ell


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MEDICAL APPLICATION* !ellcultures

• to study molecular changes that occur incancerG

• to analy0e infectious viruses8 mycoplasma8 andsome proto0oaG

• genetic or chromosomal analyses• !ervical cancer cells from a patient later

identi


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• AUTORADIOGRAPHY

•

CELL & TISSUE CULTURE

• INTERPRETATION OF STRUCTURES INTISSUE SECTIONS

INTERPRETATION OF STRUCTURES


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INTERPRETATION OF STRUCTURESIN TISSUE SECTIONS

• A"ti'cts – minor shrinkage of cells or tissue

regions produced by•

i3ative• 2thanol• Heat needed for paraBn embedding



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• A"ti'cts – wrinkles in the section$confused with linear structures such as blood

capillaries)and

– precipitates from the stain$confused with cellular structures eg.

cytoplasmic granules)



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• A"ti'cts – impossibility of diDerentially staining all

tissue components on one slide

– when a structure’s > volume is cut intovery thin sections8 the sections appearmicroscopically to have only twodimensions length and width


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;n thin sections > structures appear to have only two dimensions.Such images must be interpreted correctly to understand the actualstructure of tissue and organ.2g.8 blood vessels and other tubular structures appear in sections as

round or oval shapes whose si0e and shape depend on the transverseor obli ue an le of the cut


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T+# Cyto!lsm 6ecture


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T+# Cyto!lsm 6ecture7utline

• CELL DIFFERENTIATION

• CYTOPLASMIC ORGANELLES – Plasma 4embrane8 Libosomes8 2ndoplasmic

Leticulum8 5olgi "pparatus8 Secretory5ranules8 6ysosomes8 Proteasomes84itochondria8 Pero3isomes

• THE CYTOS9ELETON

•

4icrotubules8 4icro


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CELL DIFFERENTIATION

• Zygot# - single cell formed by unionof a spermato0oon with an oocyte

• 5lstom#"#s T product of the 'st 0ygotic cellular division – give rise to all tissue types of the fetus


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CELL DIFFERENTIATION

• Di/#"#titio

- s#eciali*ation #rocess where cellssynthesi0e increased +uantities ofs#ecic proteins for speciali0edfunctions


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CYTOPLASMIC ORGANELLES


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CYTOPLASMIC ORGANELLES

• :he cell is composed of two basic partscyto!lsm $5r. kytos3 cell3 ? #lasma3 thingformed(

%cl#%s $6. nux3 nut(

• !lsm m#m-"# 0!lsml#mm1

- outermost com#onent of the cell8separating the cytoplasm from itse3tracellular environment


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• Cytosol

– =uid component of the cytoplasm – contains hundreds of en0ymes

– &%8 !7%8 electrolytic ions8 low-molecularweight substrates8 metabolites8 andwaste products ll diDuse throughcytosol


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• O"g#ll#s

( metabolically active structures whichmay be membranous $such as

mitochondria) or nonmembranous proteincomple3es $such as ribosomes andproteasomes)

Pl M -


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Plsm M#m-"#

• aka cell membrane or plasmalemma• li#id bilayer with embedded .&9%s T

peripheral and transmembrane - $CO&F by

weight) that surrounds cell• seen only with the @5A

Pl M -


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Plsm M#m-"#

• li#id bilayer forms from amphipathic #hos#holi#ids -- % nonpolar $hydrophobic/H%&repelling) long-chain " linked to charged polar$hydrophilic/H%& attracting) head that bears a phosphate

group• stabili0ed by cholesterol• contains many embedded $integral) and

peripheral proteins on its cytoplasmic

surface

Pl M -


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Plsm M#m-"#

• membrane !H7As move laterally w/in lipidbilayer

• less movemr’t in li#id rafts ) higher conc of

cholesterol and saturated fatty acids

Pl M -


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Plsm M#m-"#

• ;ntegral $embedded) membrane proteins – directly incorporated within the lipid bilayer

itself – include

"#c#!to"s - for e3ternal ligands

c+#ls - for passive or active movm’t ofmolecules

!%m!s - for active membrane transport

Pl M -


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Plsm M#m-"#

• Peripheral proteins – e3hibit a looser association with one of

the two membrane surfaces8 particularly

inner membrane

Fl i$ M i M $ l


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Fl%i$ Mosic Mo$#l

• membrane proteins comprise amoveable mosaic within the =uidlipid bilayer

• proteins are not bound rigidly inplace and are able to move laterally

Plsm M#m-"#* 4echanisms of


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Plsm M#m-"#* 4echanisms oftransport



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Plsm M#m-"#* 4echanisms oftransport



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s # - # ec a s s otransport

Plsm M#m-"#


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Plsm M#m-"#

• 2ndocytosis – cellular uptake of macromolecules or

Buid by plasma membrane engulfment

or invagination8 followed by the“#inching oC” of a


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4a1or types ofendocytosis –

phagocytosis $uptakeof #articulate material) – pinocytosis $uptake

of dissolved

substances) – receptor-mediated

endocytosis $uptakeof speci


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M#m-"#

• 23ocytosis – type of cellular

secretion in whichcyto#lasmic membrane vesiclesfuse with the #lasmamembrane and releasetheir contents to the

e3tracellular space – bulk movement of

large molecules frominside to outside the

cell

Plsm M#m-"#


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Plsm M#m-"#

• All types of cell signaling usemembrane rece#tor #roteins that areoften linked to en0ymes such as

kinases or adenylyl cyclase whoseactivities initiate intracellularsignaling pathways

Ri-osom#s


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Ri-osom#s

• :he two ribosomal subunits8 each acomple3 of r4%2 and many proteins8attach to m4%2 and translate that

message into protein

Ri-osom#s


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Ri-osom#s

• 4ultiple ribosomes on the samemLA" make up a #olyribosome$#olysome( produces basophilic

cytoplasm after H92 staining

E$o!lsmic


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!R#tic%l%m

• convoluted network ofmembrane enclosingcontinuous spaces

called cisternae ande3tending from thenucleus to the plasma

membrane

E$o!lsmic R#tic%l%m


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E$o!lsmic R#tic%l%m

• Lough 2L – has granular3 baso#hilic cytoplasmic

surface due to the presence of

polysomes – l3ys well developed in cells actively

secreting #roteins

E$o!lsmic R#tic%l%m


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E$o!lsmic R#tic%l%m

• Proteins to be processed through theL2L contain initial signal peptideswhich bind receptors in the 2L

membrane8 locali0ing them to thatorganelle

E$o!lsmic R#tic%l%m


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E$o!lsmic R#tic%l%m

• @ranslocation across membrane cisterna .&9%s undergo

#osttranslational modication D

folding in a process monitored byL2L molecular chaperones anden0ymes

E$o!lsmic


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R#tic%l%m

• Smooth 2L $S2L) – lacks ribosomes – has en0ymes for

li#id and glycogenmetabolism

detoxicationreactions

tem#orary .a'? seEuestration

Golgi A!!"t%s


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Golgi A!!"t%s

• a dynamic organelle consisting ofstacked membranous cisternae inwhich #roteins made in L2L are

#rocessed further and #ackaged forsecretion or other roles

Golgi A!!"t%s


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Golgi A!!"t%s

• Proteins in transport vesicles enterthe cis or receiving face of the 5olgi move through medical cisternae of

the 5olgi network for en*ymaticmodicationsreleased in othervesicles at the trans face

Golgi A!!"t%s


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Golgi A!!"t%s

Golgi A!!"t%s


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Golgi A!!"t%s

• ;mportant protein modi


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Lysosom#s

• Lysosom#s $5r. Fysis3 solutionG Usoma3 body)

• P"im"y lysosom#s emerge fromthe 5olgi apparatus containinginactive acid hydrolases speci


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Lysosom#s

• S#co$"y lysosom#s are moreheterogeneous8 having fused withvesicles produced by endocytosis

that contain material to be digestedby the hydrolytic en0ymes.

Lysosom#s


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Lysosom#s

• "utophagy – lysosomes digest unneeded or

nonfunctional organelles after these are

surrounded by membrane that thenfuses with a lysosome

Lysosom#s


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Lysosom#s

• Products of digestion in secondarylysosomes are released to thecytoplasm for reuse

• R#si$%l -o$i#s -


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P"ot#som#s


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P"ot#som#s

• small cytoplasmic !H7A comple3eswhich degrade im#ro#erly folded

#roteins after they are tagged with

the polypeptide %-i:%iti

Mitoc+o$"i


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Mitoc+o$"i

• $5r. mitos3 thread3 ? chondros3 granule(• ma1or sites of 2@G synthesis • abundant in cells or cytoplasmic regions

where large amounts of energy aree3pended• speciali0ed for aerobic res#iration and

production of adenosine triphosphate

$":P)8 with high-energy phosphate bonds8which supplies energy for most cellularactivities

Mitoc+o$"i


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Mitoc+o$"i

• usually elongated organelles• form by


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Mitoc+o$"i

• 4itochondria havetwo membranes – #orous outer

membrane enclosesintermembranespace

– inner membrane

with many folds$cristae) enclosinggel)like matrix

Mitoc+o$"i


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Mitoc+o$"i

• mitochondrial matri3 containsen0ymes for H)oxidation of fattyacids and the citric acid $Irebs( cycle

• inner membrane includes en0ymeassemblies of electron)trans#ort

system and 2@G synthase

Mitoc+o$"i


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Mitoc+o$"i

• 4itochondria of stressed cells mayrelease cytochrome . from the innermembrane triggering a regulated

series of events culminating in celldeath $a#o#tosis(

P#"o)isom#s


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P#"o)isom#s

• small spherical organelles containingen*ymes for oxidation anddetoxication8 and catalase that

breaks down the by-product &'9'

Cytos;#l#to


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Cytos;#l#to

• contains three types of polymers – Aicrotubules %O nm diameter – 2ctin


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Cytos;#l#to

• 4icrotubules – semirigid tubular structures with walls

composed of #olymeri*ed tubulin

heterodimers – dynamic structure with steady addition

and dissociation of tubulin

Cytos;#l#to


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Cytos;#l#to

• 4icrotubules – maintains cell shape – tracks for transport of vesicles and

organelles by the motor #roteins )kinesin and dynein

Cytos;#l#to


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Cytos;#l#to

• 4icro


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Cytos;#l#to

• 4yosins – motor proteins that bind and move

along actin


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Cytos;#l#to

• Gur#ose of movements of cytoplasmproduced by actin and myosin – 2ndocytosis –

!ell cleavage after mitosis – !ell locomotion on substrates

Cytos;#l#to


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Cytos;#l#to

• ;ntermediate


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c %s o s

• not metabolically active• primarily storage sites

– such as lipid droplets8 glycogen

granules8 pigment granules8 or residualbodies $lipofuscin)

E6#"yt+ig $#!#$s o YOUR!oit o' 6i#3


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!oit o' 6i#3

:he only way to do great work is to love what you do. ;f youhaven’t

found it et kee lookin >on’t settle --- Steve obs

Leminder


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• %& item e3am ne3t week 't#" the lecture• '& items from ne3t week’s lecture$so pay attention during class)

• '& items from today’s lecture$because repetition plays a role in reinforcing

memory)

•

;t’s not 1ust about the ?:o >o [email protected] it’s more on the ?Aot :o >o6ist@.


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Documents

Histo Lec 1 Tissue Prep & Cyto