2a + 2b: Proteome and Protein Synthesis Flashcards
what is a lysosome
-membrane bound organelle
- contains variety of hydrolases which digest proteins, lipids, nucleic acids, carbohydrates.
- use water to break covalent bonds
what do vesicles do
transport materials between membrane compartments.
what is the golgi apparatus
series of flattened membrane discs
Where are lipids synthesised
SER
Then inserted into its membrane
Where are cytosolic proteins completed
cytosolic ribosomes.
Then remain in the cytosol
what is a signal sequence (transmembrane proteins)
a short stretch of amino acids at one end of the polypeptide which determines the location of a protein in the cell.
Translation continues after docking, and the protein is inserted into the membrane of the ER
What happens to proteins as they move through the golgi apparatus
post- translational modifications
What happens to a protein after the ER
transported by vesicles that bud off from the ER, travels, then fuses with the golgi apparatus.
What happens to a protein after the golgi apparatus
vesicles take proteins to the plasma membrane and lysosomes
What do vesicles travel through to get to other membranes
microtubules
Where are secreted proteins translated in
ribosomes in the RER
(buds of RER to go to golgi apparatus by vesicle)
Where to secretory vesicles go
fuses with plasma membrane and releases protein outside of cell
Example of secretory enzyme
digestive enzymes eg trypsin
Many secreted proteins are inactive. They require ____ to become active
proteolytic cleavage
what is proteolytic cleavage
a type of post-translational modification where the polypeptide is cut
Example of secreted enzymes that require proteolytic cleavage to become active
digestive enzymes
Define proteome
the entire set of proteins expreesed by a geonome
factors which can affect the set of proteins expressed by a given cell type
- Metabolic activity
- cellular stress
- response to signalling molecules
- diseased versus healthy
What name is given to genes that do not code for proteins
Non-coding RNA genes
Endoplasmic Reticulum definition (ER)
the endoplasmic reticulum forms a network of membrane tubules continuous with the nuclear membrane.
RER- ribosomes on cytosolic face
SER- lacks ribosomes
Transmembrane proteins carry a signal sequence which…
halts translation of the protein at the cytosolic ribosome and directs the ribosome synthesising the protein to dock with the ER, forming RER
