BIOL 3301 Lecture Notes - Lecture 13: Secretion, Protein Aggregation, Endomembrane System
Lecture 13 – endocytosis and exocytosis
- Getting stuff out of the cell and into the cell
- The cell rearranges itself to phagocytize something like a bacterial cell, something bigger than itself
2 main ways to carry proteins to the cell surface/outside of the cell:
1) Constitutive secretory pathway (secretion out to the cell)
2) Signal-mediated diversion to lysosomes (ex. Neurotransmitters, things that wait for a signal).
a. Vesicles are densely packed after whilst waiting for the signal to secrete
- Things exit cells via vesicles
Regulated secretion
- For cells that are secreted in response to a stimulus (NT’s, hormones, digestive enzymes)
- Sorting is controlled by a selective protein aggregation in trans-golgi, will pinch off a lot of the extra
membrane in order to form the mature secretory vesicle
- The vesicle then waits for a signal to merge with the membrane
- Clathrin coat dissociates before the secretory vesicle and the coat buds into an empty vesicle
Synaptic vesicles in nerve cells – shows entire endomembrane system
- Proteins can come from the golgi network or from vesicles in the membrane
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Document Summary
Getting stuff out of the cell and into the cell. The cell rearranges itself to phagocytize something like a bacterial cell, something bigger than itself. 2 main ways to carry proteins to the cell surface/outside of the cell: constitutive secretory pathway (secretion out to the cell, signal-mediated diversion to lysosomes (ex. Neurotransmitters, things that wait for a signal): vesicles are densely packed after whilst waiting for the signal to secrete. For cells that are secreted in response to a stimulus (nt"s, hormones, digestive enzymes) Sorting is controlled by a selective protein aggregation in trans-golgi, will pinch off a lot of the extra membrane in order to form the mature secretory vesicle. The vesicle then waits for a signal to merge with the membrane. Clathrin coat dissociates before the secretory vesicle and the coat buds into an empty vesicle. Synaptic vesicles in nerve cells shows entire endomembrane system. Proteins can come from the golgi network or from vesicles in the membrane.
