بسم الله الرحمن الرحيم. The cell By Prof. Dr. Nahed Zohdy Professor of Histology...
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Transcript of بسم الله الرحمن الرحيم. The cell By Prof. Dr. Nahed Zohdy Professor of Histology...
الرحمن الله الرحمن بسم الله بسمالرحيمالرحيم
The cellThe cellByBy
Prof. Dr. Nahed ZohdyProf. Dr. Nahed Zohdy
Professor of Histology & Professor of Histology & Cell BiologyCell Biology
About this LectureAbout this Lecture
CytoplasmCytoplasm::
StructureStructure
OrganellesOrganelles
RibosomesRibosomes
ERER
Golgi apparatusGolgi apparatus
LysosomesLysosomes
MitochondriaMitochondria
Haematoxylin and Eosin Haematoxylin and Eosin (H&E)(H&E)
• HaematoxylinHaematoxylin is a basic violet stain. is a basic violet stain.
•EosinEosin is an acidic pink stain. is an acidic pink stain.
• Acidophilic structureAcidophilic structure= A structure = A structure that has affinity to stain with acidic that has affinity to stain with acidic dyes = basic in nature………So it stains dyes = basic in nature………So it stains pinkpink with eosin with eosin
•Basophilic structureBasophilic structure= A structure that = A structure that has affinity to stain with basic dyes = has affinity to stain with basic dyes = acidic in nature……… So it stains acidic in nature……… So it stains violetviolet with haematoxylinwith haematoxylin
Composed ofComposed of::
11-- CytosolCytosol:: jelly like fluid jelly like fluid
matrix, its matrix, its primary primary component is component is waterwater
22-- OrganellesOrganelles
33 - -InclusionInclusion
44 - -CytoskeletonCytoskeleton
The cytoplasmThe cytoplasm
Nucleus
cytoplasm
OrganellesOrganellesLittle organs:
-Living structures
-Metabolicaly active -Perform certain functions
-Permenant
-Present in all cell types Types:
- Memberanous organelles- Non-membranous organelles
RibosomesRibosomes - - Non-membranous organellesNon-membranous organelles
- - Chemical nature: Chemical nature: nucleoproteinsnucleoproteins consist consist of proteins of proteins conjugated with ribosomal RNA conjugated with ribosomal RNA (rRNA)(rRNA)-Structure:Structure:
LMLM:: By H&E stain: can not be seenBy H&E stain: can not be seen if large in number they impart if large in number they impart
Cytoplasmic basophiliaCytoplasmic basophilia..
Electron dense granulesElectron dense granules
22 subunitssubunits : :
Small subunit (RNA+30 P)Small subunit (RNA+30 P)
large subunit (2RNA+40 large subunit (2RNA+40 P)P)
EMEM::
Types of ribosomes
Free Attached
Solitary Polysomes
PolysomesPolysomes
- -Clusters of ribosomes connected Clusters of ribosomes connected by mRNA thread & producing by mRNA thread & producing identical proteinsidentical proteins
mRNA
ribosomes
Free protein in cytoplasm
Attachment of ribosmes to the Attachment of ribosmes to the rERrER
EM of attached ribosomesEM of attached ribosomes
Function of ribosomesFunction of ribosomes
Ribosomes are the sites of are the sites of protein protein synthesissynthesis::
SolitarySolitary: reserve: reserve
PolysomesPolysomes: proteins used by the cell: proteins used by the cell
AttachedAttached: proteins for secretion : proteins for secretion outside the celloutside the cell
Endoplasmic reticulumEndoplasmic reticulum - -Membranous organelleMembranous organelle
- -Network of interconnecting tubules and cisternae
Endoplasmic reticulum
Rough
(rER)
Smooth
(sER)
rERrER
Cyto. basophaliaCyto. basophalia
Cyto. acidophilia
sERsERLMLM
rERrER- - Interconnected Interconnected parallelparallel
cisternaecisternae- - Has attached ribosomesHas attached ribosomes- - Connected to nuclear mConnected to nuclear m..
--Interconnected Interconnected branching branching tubulestubules
--Lacks ribosomesLacks ribosomes----No connection with No connection with
nuclnucl..
sERsEREMEM
rERrER
Interconnected Interconnected cisternaecisternae
Has attached ribosomesHas attached ribosomes
Interconnected Interconnected tubulestubulesLacks ribosomesLacks ribosomes
sERsEREMEM
rERrER
Participates in Participates in protein synthesisprotein synthesis..
11-- Lipid synthesis Lipid synthesis (fatty acids ,cholestrol & (fatty acids ,cholestrol & steroid hormones)steroid hormones)
22 - -Detoxification of Detoxification of toxic substancetoxic substance
33 - -Muscle Muscle contractioncontraction
))control calcium ions -control calcium ions -sarcoplasmic reticulumsarcoplasmic reticulum((
44 - -Glycogen Glycogen synthesissynthesis
sERsERFunctionFunction
Role of rER in protein Role of rER in protein synthesissynthesis
1 -receiving of polypeptide chains in ER lumen2 -storage
3 -protein trasport
Golgi apparatusGolgi apparatus
-Membranous organelle-Membranous organelle
Structure:Structure:LM:LM: --H&E stain: not apparentH&E stain: not apparent
- -Special stain: Special stain: silver stainsilver stain
Golgi apparatus in Golgi apparatus in epididymisepididymis(Silver stain)(Silver stain)
Brown anastomosing network of threads at the secretory border of the cells
EM structure of Golgi EM structure of Golgi apparatusapparatus
3 components:
-macrovesicles
-flattened membranous saccules. (4-10)
-microvesicles
Flattened membranous cisternae:
Convex surface: immature face
Concave surface: Secretory face = mature face
Fate of protein transported Fate of protein transported by rERby rER
Fate of protein transported Fate of protein transported by rERby rER
Primary lysosomes
Functions of Golgi Functions of Golgi apparatusapparatus
1 -Chemical modification of proteins22 - -Formation of primary lysosomesFormation of primary lysosomes
33 - -Secretion of cell productsSecretion of cell products 44 - -Renewal of the cell membraneRenewal of the cell membrane
Cytoplasmic Organelles Cytoplasmic Organelles that participate in the that participate in the
process of process of protein protein synthesissynthesis
11 - -Ribosomes Ribosomes (factories)(factories)
22 - -Rough endoplasmic reticulum Rough endoplasmic reticulum (storage & transport)(storage & transport)
33 - -Golgi apparatus Golgi apparatus (chemical (chemical modification & secretion)modification & secretion)
LysosomesLysosomes
DefinitionDefinition:: -Membrane bound organelles containing
hydrolytic enzymes
)Digestive system of the cell(
StructureStructure::
LMLMHistochemical Histochemical methods methods staining staining their enzymestheir enzymes
LysosomesLysosomes -Membrane bound organelles containing
hydrolytic enzymes
EMEM22 typestypes
1ry lysosome
small, regular vesicle , contains homogenous dense content
2ry lysosome
Large, irregular vesicle, contains heterogenous dense and light contents
Function of lysosomesFunction of lysosomes
-The digestive system of the cell (contain hydrolytic enzymes that could digest the food vacuole's contents & destroy old cell organelles)
Formation of the 2 types of Formation of the 2 types of lysosomeslysosomes
Forms of secondary Forms of secondary lysosomeslysosomes
1ry lysosome + 1-pinocytotic vesicles = multivesicular body
2 -phagosomes =residual bodies
3 -autophagic vacuole = residual bodies
5 -Lipofuscin pigment
MitochondriaMitochondria
-Membranous organelles-Membranous organelles
Structure:Structure:LM:LM: --H&E stain: not apparentH&E stain: not apparent
- -Special stain: Special stain: silver stainsilver stain
Mitos= thread chondros= granule
LM picture of mitochondria LM picture of mitochondria (special stain: silver stain)(special stain: silver stain)
mitochondria appear as mitochondria appear as dark brown granules granules
EM of the Mitochondria
Double membranes:
-Outer smooth-Inner folded
forming cristae
Double spaces: -
intermembranous space
- intercristal space (matrix space)
intermembranous space
Inner membrane: -cristae to increase
surface area - contains protein
enzymes for respiratory chain
- contains ATP synthetase for ATP synthesis Matrix:
-oxidative enzymes - mitochondril DNA so mitochondria can replicate themselves
--Energy productionEnergy production & storage & storage (ATP synthesis)(ATP synthesis)
--Concerned with Concerned with cell cell respiration respiration (sites for Kreb’s (sites for Kreb’s and fatty acid cycles)and fatty acid cycles)
Function of a mitochondrion
LM:LM:can not be seencan not be seen
EM:EM:- - small, roundedsmall, rounded- similar to 1ry - similar to 1ry lysosomeslysosomes
- Contain 40 oxidative enzymes - Contain 40 oxidative enzymes (urate oxidase)(urate oxidase)
PeroxisomesPeroxisomes
Functions of Functions of peroxisomesperoxisomes::
1- Generate energy but can not store it 1- Generate energy but can not store it ((NO ATP formationNO ATP formation))
2- Maintenance of body temperature (The 2- Maintenance of body temperature (The energy is released as heat).energy is released as heat).
33 - -Cell protection : catalase enzymeCell protection : catalase enzyme
breaks down Hbreaks down H22OO22..
Thank youThank you