2F-Secretory Pathways Flashcards
KEY TERM - Exocytosis
A type of bulk transport that moves large substances out of the cell.
KEY TERM - Vesicle
A small fluid-filled organelle that transports substances around the cell.
KEY TERM - Bulk transport
The movement of Molecules across a membrane requiring an energy input.
KEY TERM - Rough Endoplasmic Reticulum
An organelle shaped like a series of connected, flattened, cylinders that folds and transports proteins via it’s attached ribosomes.
KEY TERM - Golgi apparatus
An organelle made of flattened sacs of membrane involved in modifying, sorting, and packaging proteins.
Two types of Bulk transport
Endocytosis and Exocytosis
What is passive transport
No energy costs
What is active transport
Has energy costs
First step of Exocytosis
1- A vesicle forms around the molecules and is moved over to the plasma membrane.
Second step of Exocytosis
The membrane of the vesicle and plasma membrane fuse.
Proteins leave the cell via what way?
Exocytosis
The process of proteins leaving the cell goes-
The protein is translated in a ribosome that is located on the rough endoplasmic reticulum.
When its leaving the Endoplasmic Reticulum, what happens to the proteins?
They have been put into a transport vesicle.
What does the rough Endoplasmic Reticulum do to the proteins?
They enter the Reticulum to start the secretory process, they go here to get organised on where they will be distributed to.
The three sides of the Golgi Apparatus are:
Cis, Medical(actual side), and trans.
When is a transport Vesicle, where do the proteins travel to?
The Golgi apparatus/body
What does the Golgi apparatus do to Proteins?
It further packages the proteins, ensuring the info is correct, taking this out like, phosphates, sugars, sulphates etc etc.
What is the first of the 3 final steps of a Secretory Vesicle leaving a cell through the plasma Membrane?
1 - The cargo proteins (that are getting secreted) join to the membrane-bound-receptor protein, changing their shape.
How do proteins move out of the Golgi Apparatus?
On the trans side, little pieces can bud off and turn into secretory Vesicles, which make their way over to the Plasma Membrane.
What is the second last step of a protein leaving through the plasma membrane?
Little motor proteins drag the vesicle along the cytoskeleton to the membrane.
Whats the final step of exocytosis?
The plasma membrane protein has a distinct shape, and the enzymes inside the vesicle tell the vesicle to change shape so it can bind to a certain membrane protein, telling it where to go. the little motor protein takes the shaped vesicle to its complementary shaped protein, and then leaves the cell there.
What is Endocytosis?
Where a large molecules or a large amount of molecules get transported into the cell.
What are the three words to remember in endocytosis?
- FOLD
- TRAP
- BUD
what is the FOLD step in endocytosis
A fold occurs in the plasma membrane which contain extracellular fluids.
What is the step TRAP in endocytosis
The extracellular fluid is trapped in the fold
What is the step BUD in endocytosis
The vesicle pinches away from the membrane to the appropriate location.
