Endomembrane 4/2 Flashcards
Explain the concept of autoradiography and experiments and its uses in the cell
visualization
Visualizing the synthesis and transport of proteins by making certain tissue sections radioactive and detecting radioactivity.
o What does audiography this illustrate? Why/how does this help our understanding of cells?
* Differentiate co-translational versus post-translational import of proteins by explaining each
process and how proteins determine their locations
Autoradiography shows where proteins are formed and where they go. This gives us a more in depth understanding of the relationships of proteins/organelles with other organelles
o What part(s) of proteins enables their correct localization? How do they “know” where
to go?
GTP, which can act as a lipid anchor. They’ll bind to the correct cells because they’re built to interact with them
TOM structure
receptors to recognize/bind mitochondrial proteins and protein-lined to let unfolded polypeptides through
Explain the concept of pulse-chase experiments and its uses in the cell
visualization
Briefly incubating tissue with radioactivity and exposing it to amino acids, letting it synthesize proteins, showing the path of the proteins throughout the cell and where they’re used/relationships between organelles
TIM structure
Barrell of 8 alpha helices, 8 beta strands
Functions of smooth ER
Detoxification of harmful substances
Lipid synthesis
Calcium ion storage
How are proteins incorporated into luminal space/embedded into lipid bilayer of smooth ER? How is asymmetry achieved?
What is the function of rough ER?
Protein synthesis, folding, and sorting
How are proteins incorporated into luminal space/embedded into lipid bilayer of Rough ER? How is asymmetry achieved?
Cargo proteins bind to appropriate receptors, and membrane carriers bud from one compartment and fuse to the next
What is the structure of rough ER?
a network of flattened sacs (cisternae),with each layer connected to neighbors by helicoidal membranes. continuous w/ outer membrane of nuclear envelope, w/ ribosomes on cytosol surgace). sheets fragment into rough-surfaced vesicles
- Explain in detail the process of getting proteins to and through the membranes of the
mitochondria, whether fully imported or embedded
- Polypeptide binds to mitochondria by search sequence on N terminus
- Proteins rexognized by TOM, brought in
- Proteins go through TIM23 of IMM
- Proteins refolded by chaperone
- Refolded, presequence removed
