this slide is about the vascular traffic of cells in biochemistry. and this slide you get more information about cells and how cells transport their protein.
14. Oligosaccharide processing in the ER and the Golgi apparatus
• A single species of N-linked oligosaccharide is attached to many proteins
in the ER and then trimmed while the protein is still in the ER.
• Further modifications and additions occur in the Golgi apparatus,
depending on the protein.
• The outcome is that two broad classes of N-linked oligosaccharides, the
complex oligosaccharides and the high-mannose oligosaccharides, are
found attached to mammalian glycoproteins
• Complex oligosaccharides are generated by a combination of trimming the
original N-linked oligosaccharide added in the ER and the addition of
further sugars.
• By contrast, high-mannose oligosaccharides have no new sugars added to
them in the Golgi apparatus.
• Whether a given oligosaccharide remains high-mannose or is processed is
determined largely by its position on the protein.
• If the oligosaccharide is accessible to the processing enzymes in the Golgi
apparatus, it is likely to be converted to a complex form; if it is inaccessible
because its sugars are tightly held to the protein's surface, it is likely to
remain in a high-mannose form.
