The Golgi Apparatus modifies proteins and synthesizes lipids. It is composed of stacks of flattened sacs called cisternae that contain enzymes. As proteins pass through the cis, medial, and trans cisternae, the Golgi enzymes modify them via glycosylation, acetylation, and phosphorylation. The Golgi also synthesizes sphingomyelin and glycolipids. It sorts proteins to lysosomes for degradation or to the plasma membrane via direct transport, endosomes, or the regulated secretory pathway. Vesicles play an important role in transporting molecules between membranes and compartments with the help of GTP-binding, adaptor, and coat proteins.

1. The Golgi Apparatus
Presented by: Rahul Kumar
M.Sc 1st Sem.
Life Science
CUG/2014/1073

2. Contents
History
Organization of Golgi
Functions of the Golgi
.Protein modification
.Synthesis of Sphingomyelin &Glycolipid
.Sorting of protein to lysosome
.Sorting of protein to plasma membrane
 Vesicles

3. History
Discovered by Italian
physician Camillo Golgi during
an investigation of the nervous
system in 1898 – internal
reticular structure.
Optical illusion created by the
observation technique used by
Golgi.
This structure was confirmed in
1910 as a Golgi apparatus/
Golgi bodies.

4. Organization of Golgi
• Found within the cytoplasm of both plant and
animal cells.
• It is composed of stacks of membrane-bound
structures - cisternae (singular: cisterna)
• Each cisterna comprises a flat, membrane-
enclosed disc that includes special Golgi
enzymes which modify or help to modify
cargo proteins that travel through it.

5. • Consists of 4 functionally distinct region- cis
face (entry face), medial cisterna, trans cisterna,
trans face(exit face).
• Each region contain different enzymes which
selectively modify the contents depending on
where they reside.

6. Functions of the Golgi:
E.R Golgi Secretion
P.M
Endosome
Lysosome
Modification
Of protein
Synthesis
Glycolipid &
Sphingomyelin

7. Protein modification
• Start in the E.R after translation - addition of 2
N-acetylglucosamine & 9 mannose.
• In Golgi, glycosyltransferase & glycosidase is
present – help in addition & removal of sugar
residues in N-linked oligosaccharides.

8. Processing of N-linked oligosaccharides in the
Golgi :

9. Synthesis of Sphingomyelin & Glycolipid

10. Sorting of protein to lysosome:

11. Sorting of protein to plasma memsbrane:
• Take place via 3 routes
direct transport from trans golgi .
via an intermediate of endosome .
regulated secretory pathway .

13. direct transport from trans golgi-
- In corporation of new protein(peripheral as
well as integral) & lipid to the p.m .
- continuous secretion of protein from the cell.
- linear targeting signals.

14. via an intermediate of endosome
• in the epithelial
cells by transcytosis
• ex.- transport of
antibodies to
extracelluar fluid.

15. regulated secretory pathway
• Play an important role in
- release of neurotransmiter
-release of hormones
- release of digestive enzymes

16. Vesicles
• Important role in transport of mole. Between
different membrane or compartment of cell.
• Formation of vesicles require –
-GTP binding protein (ex. Arf, Rab)
-Adaptor protein
-Coat protein (copl, copll, clatrin)

17. THANK YOU