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The Golgi is said to be __.
- thickness?
- membranes?
Faces
- polar: different faces
- -varies
- - membranes at the cis face are like the RER (where things enter)
- - membranes at the trans face are exactly or close to plasma membrane
cis: determines whether they can go on or whether they shuld go somewhere else
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Diameter of the Golgi?
Orientation?
- 1/2 a micrometer
- - some bigger, some smaller
- - tubules around the outside
- there's a space between cisternae (300 angstroms); not stacked directly
- - some sort of connection (protein) holding them
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Regions of the Golgi?
Cis Golgi network: region where alot of vesicles fuse and come into contact with the ER
Cis region: proximal pole; forming face [receives things from the ER]
Medial region
Trans region: distal pole; maturing face
trans golgi network: alot of tubules are found here; vesicles form
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The golgi complex is a source of __ for the __.
- membrane material
- plasma membrane
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How many cisternae per stack?
- varies among organisms
- common number is 3-7
- sometimes, there's only one
- tubules around it confirm its Golgi
- some can have twenty
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Suggestions of transport between the RER and the Golgi Complex (which is kind of circular)
structurally continuous vs. structurally discontinuous
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Structurally continuous: ??
Structurally discontinuous: ??
connection between the two (not likely)
- no connection; material gets to Golgi through a series of vesicles; more logical; vesicles pinch off in a location where there are no ribosomes attached; starts to fuse with the Golgi
- (transition/ transport vesicles)--> transport proteins made in the ER lumen to Golgi
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What are the two models of transport through the Golgi?
- cisternal maturation model
- vesicular transport model
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Cisternal maturation model
- -they transport (vesicles)
- -if there's alot of vesicles forming, what increases are the cisternae; new ones form, while otheres are pushed from cis to trans
- - they get pushed to the top
- - broken up to form transport vesicles
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Scale method of Golgi:
- The scales are formed progressively within single __ of the Golgi apparatus as the __ mature.
The mature cisternae then do what?
With certain scales, called __, __ occurs at the scale margin prior to discharge of the scale to the cell surface.
- cisternae x2
- separate from the stack and the cisternal membranes fuse with the plasma membrane to discharge the individual scales
- coccoliths
- calicification
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Vesicular transport model
movement of materials from cis to trans cisternae of the Golgi complex via shuttle vesicles
materials go from one place to the other through shuttle vesicles, whcih fuse from one to the other. The cisternae don't catually move. Shuttle vesicles do all the moving
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Autoradiography:
-Step one and two
- cells exposed to radioactive compound, washed and fixed, and embedded in wax or plastic
- sectioned and placed on slide (or copper grid if using EMs)
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In the experiment with pancreas, what was it immersed in? Why is it washed?
- in experiment with pancreas, it was amino acids
- - wash to get rid of excess radioactivity
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Autoradiography:
- Step three and four
dipped in photographic emulsion and stored in dark
- developed and viewed
- - AgBr crystal activated and hits emulsion, causing grain to form
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When is the only time you expose to grains or emulsion?
in the pulse period
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Condenser vesicles
- loses water
- (recondensing whatever is in the vesicle)
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Within __, cells are making __, which are already being __.
- 1.5 hours
- proteins
- secreted from the cell
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You can graph the pulse-chase period for what?
to see progression
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