2. • It also called Golgi body or Golgi apparatus .
• Golgi apparatus is a membrane – bond organelle found in eukaryotic
cells .
• It was first observed by Italian cytologist “ Camillo Golgi ” during an
investigation of the nervous system .
• He termed it as internal reticular apparatus according to its shape
which like curved network .
3. LOCATION IN CELL
• The subcellular localization of the “ Golgi complex “ varies among
eukaryotes.
• It is usually located near the cell nucleus close to endoplasmic
reticulum.
• While many types of cells contain only one or several Golgi
apparatus, plant cells can contain hundreds.
4.
5. THE STRUCTURE
• The Golgi apparatus itself is structurally polarized , with three primary
compartments lying between the “cis” and the “trans” face.
• The enzymatic content of each segment is markedly different. The cis face
membranes are generally thinner than the others.
• The Golgi apparatus is made up of approximately four to eight cisternae and in
some single-celled organisms it may consist of as many as 60 cisternae.
• The cisternae are held together by matrix proteins, and the whole of the Golgi
apparatus is supported by cytoplasmic microtubules.
6. • The three primary compartments of the apparatus are known generally as “cis”
(cisternae nearest the endoplasmic reticulum), “medial” (central layers of
cisternae), and “trans” (cisternae farthest from the endoplasmic reticulum).
• Cisternae at the cis and trans faces, are responsible for the essential task of
sorting proteins and lipids that are received (at the cis face) or released (at the
trans face) by the organelle.
7.
8. THE FUNCTION
• The vital function of the Golgi apparatus is packaging and secretion of proteins.
• It receives proteins from Endoplasmic Reticulum.
• It packages it into membrane-bound vesicles, which are then transported to
various destinations, such as lysosomes, plasma membrane or secretion.
• They also take part in the transport of lipids.
9. PROTEIN AND LIPID MODIFICATION
• The proteins and lipids received at the cis face arrive in clusters of fused vesicles.
• When a vesicle cluster fuses with the cis membrane, the contents are delivered into the
lumen of the cis face cisterna. As proteins and lipids progress from the cis face to the
trans face, they are modified into functional molecules and are marked for delivery to
specific intracellular or extracellular locations.
• In the final stage of transport through the Golgi apparatus, modified proteins and lipids
are sorted in the trans Golgi network and are packaged into vesicles at the trans face.
These vesicles then deliver the molecules to their target destinations, such as
lysosomes or the cell membrane.