C5.2: Membrane-bound organelles Flashcards
Golgi apparatus is named after ___, an Italian biologist who discovered the organelle
Camillo Golgi
a membrane-bound packaging organelle of eukaryotic cells found in the cytoplasm and is made up of approximately four to eight flattened, stacked pouches called cisternae
Golgi apparatus
organelles that is -situated in between the endoplasmic reticulum and the cell membrane
Golgi
the whole golgi apparatus is supported by
cytoplasmic microtubules
long, flattened and sac-like structures that are arranged parallelly in bundles
cisternae
Held together by matrix proteins exists primarily as fiber-like bridges
cisternae
GRASP:
Golgi Reassembly Stacking Protein
The volume enclosed by the membranes of any citerna or subcompartment of the Golgi apparatus, including the cis- and trans- Golgi networks
lumen
Help move the proteins from the ER and transport these proteins to the Golgi apparatus for further sorting and refining
Transport vesicles
Form from trans Golgi network and store their contents until specific signals direct them to fuse with the plasma membrane through the process of exocytosis
Secretory vesicles
Three Primary Compartments of Golgi
Cis face
medial-golgi network
trans face
- cisternae nearest the endoplasmic reticulum; entry face
Cis face
- central layers of cisternae • Pertain to the golgi sacs in between the cis- Golgi network and the trans- Golgi network
medial-golgi network
- cisternae farthest from the endoplasmic reticulum; exit face
Trans face
associated with the movement of molecules from
the endoplasmic reticulum to their final destination and the modification of certain products along the way.
Golgi apparatus
two models of golgi
Vesicular Transport Model
Cisternal Maturation Model
Vesicular Transport Model originally developed and advocated by ___ and ___
George Palade, Marilyn Farquhar
This model claims that Golgi cisternae are stable compartments that house certain protein modification enzymes that function to add or remove sugars, add sulfate groups and perform other modifications. The vital element of this model is that the cisternae themselves are stationary.
Vesicular Transport Model
This model depicts the Golgi apparatus as a far dynamic organelles as it indicates that the cis cisternae move forward and mature into trans cisternae. This occurs when a new cis cisterna is formed by the fusion of vesicles at the cis face.
Cisternal Maturation Model
Refers to the pathway in which the newly synthesized proteins and lipids from the ER are transported to the Golgi complex to the plasma membrane or other target site
Anterograde transport
The transport of proteins and lipids in the reverse direction; use as a quality control
Retrograde transport
This happens when Golgi proteins are retrieved to be recycled to the earlier compartments or when proteins/ lipids need further modifications and when they are brought in the wrong Golgi compartment.
Retrograde
The step- by- step process that a protein undergoes from the ER to the Golgi and finally to the target site
protein cargo
step-by-step process in protein cargo (5)
- Budding
- Transportation
- Fusion
- Modification
- Sorting and Tagging
The ER sends the “protein cargo” via a transport vesicle budding off from the ER exit sites.
Location:
Budding;
ER
The transport vesicle travel along the microtubule toward the cis- Golgi network/ face (entry face)
Location:
Transportation ;
Cytoplasmic microtubule
Markers and membrane proteins in the transport vesicle interact with the receptors in the cis- Golgi network and fuses with the membrane of the Golgi apparatus then releases the proteins into the Golgi lumen.
Location:
Fusion;
Cis-golgi