The document summarizes the endomembrane system and Golgi apparatus. It describes the Golgi apparatus as a smooth membrane-bound organelle found in eukaryotic cells that is involved in secretion and processing of proteins and lipids. It discusses the discovery of the Golgi apparatus, its ultrastructure consisting of stacked cisternae and vesicles, its functions in secretion, glycosylation, and formation of other organelles. The summary concludes by stating that the Golgi apparatus is an essential membrane organelle in the secretory pathway of eukaryotic cells.

1. THE
ENDOMEMBRANE
SYSTEM
PRESENTED BY AINDRILA MAJUMDAR
(BIOTECHNOLOGY-1ST YEAR)

2. 1.INTRODUCTION
2.GOLGI APPARATUS
-DEFINITIO1N
-DISCOVERY
-DISTRIBUTION AND NUMBER
-ORIGIN
-ULTRASTRUCTURE
-CHEMICAL COMPOSITION
-FUNCTIONS OF GOLGI BODY
TOPICS
TO BE
DISCUSSED

3. THE ENDOMEMBRANE SYSTEM IS COMPOSED OF
DIFFERENT MEMBRANES THAT ARE SUSPENDED IN
THE CYTOPLASM WITHIN A EUKARYOTIC CELL.
THESE MEMBRANES DIVIDE THE CELL INTO
FUNCTIONAL AND STRUCTURAL COMPARTMENTS OR
ORGANELLES, EITHER BEING CONNECTED DIRECTLY
OR EXCHANGING MATERIAL THROUGH VESICLE
TRANSPORT. IN EUKARYOTES ENDOMEMBRANE
SYSTEM INCLUDE:
- NUCLEAR ENVELOPE
- ENDOPLASMIC RETICULAM (ER)
-GOLGI APPARATUS
-LYSOSOMES
INTRODUCTION

4. GOLGI BODY
DEFINITION: GOLGI BODY IS A SMOOTH SURFACED,
RETICULAR, MEMBRANE ENCLOSED ORGANELLE OF
EUKARYOTIC CELLS CONCERNED WITH SECRETION.
DISCOVERY: CAMLLIO GOLGI (1898), AN ITALIAN
BIOLOGIST FIRST OBSERVED THIS IN NERVE CELLS,BY
SILVER STAINING METHOD & NAMED AFTER HIM,
OTHER SCIENTISTS CALL IT BY VARIOUS NAMES SUCH
AS GOLGI COMPLEX, LIPOCHONDRIA, DICTIOSOMES.

5. DISTRIBUTION ANDNUMBER:FOUNDIN ALLEUKARYOTICCELLS
EXCEPTA FEWINCLUDINGMAMMALIANRBC. GENERALLY,IN
SECRETORYCELLS,A LARGESINGLE GOLGI BODYIS PRESENT
BETWEENNUCLEUSANDCELL MEMBRANE. EXAMPLES-THYROID
CELLS,INTESTINALMUCOSALCELLS,etc. BUTIN LIVERCELLS,NERVE
CELLS,MORE THANONEGOLGI MAY BE PRESENT.
ORIGIN: THE GOLGI BODYREMAINS CONNECTEDWITH ER, AND
SUPPOSEDTO BEORIGINATED FROM ER. PROBABLYAT
FIRST,SMALL,MEMBRANEBOUNDVESICLES ARE FORMEDBY
BUDDINGFROM SER,WHICH THENJOIN ANDFUSE TOFORM
CISTERNAE.IN THE CELLSOFSOMELOWER PLANTS AND
ANIMALS,THEGOLGI BODYMAY BE FORMEDFROM THE NUCLEAR
MEMBRANEAND CELLMEMBRANE.

6. ULTRASTRUCTURE: THE SHAPE OF GOGI
BODY CHANGES FROM TIME TO TIME.
THESE ARE OF THREE TYPES –
(I) CISTERNAE OR LAMELLAE: THESE ARE
MEMBRANE BOUND FLATTENED SACS
THAT REMAIN STACKED ONE ABOVE
ANOTHER . TWO ADJACENT CISTERNAE
ARE SEPARATED BY A SMALL GAP OF
ABOUT 20-30 nm. EACH STACK OF
CISTERNAE FORMING A DICTYOSOME IS
POLARIZED STRUCTURE HAVING A
PROXIMAL OR FORMING FACE(CONVEX)
AND DISTAL OR MATURING FACE
(CONCAVE).THIS POLARIZATION IS
OFTEN REFERRED TO AS CIS-TRANS
AXIS OF GOLGI COMPLEX.
(II) VACUOLES: THESE ARE THE SWOLLEN
AND VESICULAR TERMINAL PARTS OF
CISTERNAE.
(III) TUBULES & VESICLES: THE CONVEX
SURFACE OF THE CISTERNA REMAINS
CONNECTED TO A NETWORK FORMED

7. CHEMICAL COMPOSITION: GOLGI BODY BEING AN
ORGANELLE MADE UP OF LIPOPROTEIN
MEMBRANE, ITS CHIEF CONSTITUENTS ARE
LIPID(PHOSPHOLIPID) AND PROTEIN. A FEW
ENZYMES LIKE thiamine-pyrophosphatase AND
SEVERAL glycosyl transferases.
FUNCTIONS OF GOLGI BODY:
(I) SECRETION AND TRANSPORT
(II) SYNTHESIS OF GLYCOSPHINGOLIPIDS AND
GLYCOPROTEINS & PACKAGING
(III) FORMATION OF OTHER ORGANELLES
(IV) FORMATION OF ACROSOMAL CAP OF SPERMS
(V) BIOGENESIS OF GOLGI BODY.
ZONE OF EXCLUSION: THE GOLGI COMPLEX REMAINS SURROUNDED
BY A ZONE OF CYTOPLASM WHERE MOST OF ORGANELLES ARE
ABSENT.
GERL SYSTEM: ASSOCIATED WITH TRANS FACE THERE IS OFTEN A
SACCULAR STRUCTURE THAT IS RICH IN ACID PHOSPHATASE & HAS
BEEN INTERPRETED AS A REGION OF SMOOTH ENDOPLASPIC
RETICULAM,NEAR THE GOLGI,INVOLVED IN THE PRODUCTION OF
LYSOSOMES.

8. *SECRETION:THECHIEF FUNCTIONOFGOLGI BODYIS
SECRETIONFROMA CELLOFPROTEINMATERIALS e.g.,ENZYMES,
HORMONES,NEUROTRANSMIITERS,etc.THATARENOTEASILY
DIFFUSABLETHROUGHCELLMEMBRANE.THEEXACTROLEOF
GOLGI BODYIN SECRETIONIS TO FORMLIPOPROTEIN
MEMBRANE BOUNDVESICULRPACKETSOF THESECRETORY
MATERIAL.
*GLYCOPROTEINFORMATION:GOLGI BODYTAKESPARTIN THE
SYNTHESISOFGLYCOPROTEIN(e.g. mucin) AND
GLYCOSPHINGOLIPIDMATERIAL.THE PROTEINPARTIN THESE
MATERIALSAREFORMEDIN RER,ANDTHENCOMBINEDWITH
THE SUGARDERIVATIVESIN GOLGIBODYTOPRODUCE
GLYCOPROTEINS.
*FORMATIONOFOTHERORGANELLS:THE CELLWALLANDCELL
MEMBRANECONTAINVARIOUSGLYCOPROTEINMATERIALS
THAT AREFORMEDIN GOLGIBODY.THEGOLGI BODYALSO
HELPSIN THE FORMATIONOFLYSOSOMES.
*ACROSOMEFORMATION:THE GOLGI BODYPLAYSAN
IMPORTANTROLEIN THE FORMATIONOFOFACROSOMALCAP
DUIRING SPERMMATURATION.

9. THE GOLGI IS AN ESSENTIAL MEMBRANE
BOUND ORGANELLE IN SECRETORY
PATHWAY OF EUKARYOTIC CELLS. IN
MAMMALIAN CELLS, THE GOLGI STACKS ARE
INTEGRATED INTO A CONTINUOUS
PERINUCLEAR RIBBON, WHICH POSSES A
CHALLENGE FOR THE DAUGHTER CELLS TO
INHERIT THIS MEMBRANE ORGANELLE
DURING CELL DIVISION. TO FACILITATE
PROPER PARTITIONING, THE MAMMALIAN
GOLGI RIBBON IS DISASSEMBLED INTO
VESICLES IN EARLY MITOSIS. FOLLOWING
SEGREGATION INTO THE DAUGHTER CELLS, A
FUNCTIONAL GOLGI IS REFORMED. HERE WE
SUMMARIZE OUR CURRENT UNDERSTANDING
OF THE MOLECULAR MECHANISMS THAT
CONTROL THE MITOTIC GOLGI DISSAMBLY
AND POSTMITOTIC RESSEMBLY CLCLE IN
MAMMALIAN CELL.
MECHANISM OF GOLGI BIOGENESIS :

10. THANK
YOU