B: Transmembrane Proteins, Golgi, COP (20) Flashcards
What is peroxisome? Whats its function?
Peroxisome - small organisms found in all types of cells
Main chemical reaction is breaking down hydrogen species that are toxic to cells
– Keeps track of catalase that converts hydrogen peroxide to hydrogen and water
What is the distinctive feature of preoxisome
Distinctive feature is crystalline core causing darker core
How do corrector proteins help with CF
Use drugs that helps reform 3D shape of protein to prevent degradation
These drugs bind to CRFR protein and help protein bind properly
How is cystic fibrosis caused
One AA absence disrupts channel of TFTR
– TFTR channel allows equalibriation of water and salts on surface of cells
Protein does not fold properly, cells recognize as misfolded protein and rapidly create alternate pathway
How are transmembrane proteins are integrated into the membrane
Proteins with signal-anchor sequence are threaded through a channel in the ER membrane until the signal anchor sequence is encountered
The ER channel releases the protein into the membrane
When translation is completed, the protein remains in the membrane
Where is all protein first synthesized
Proteins synthesized completely in the cytoplasm first
How do proteins reach their target locations?
N-terminal sequences, also called signal sequence, direct proteins to their respective organelles
When they arrive at the organelles other intrinsic sequences within the protein directs them to the correct compartment or membrane
What are the 2 options for protiens synthesized in the ER
1) Remain in ER lumen
2) Transported from the ER to the golgi for further modification and delivered to distal parts of biosynthetic secretory pathways
What is the structure and location of the golgi (simplified)
Golgi complex has more rounded shape structures
Intermediate structure between plasma membrane and ER
What is the main function of the golgi
Intermediate structure between plasma membrane and ER
All protein that are supposed to be trafficked elsewhere will be trafficked into this structure
What is the structure of the golgi complex
Average each cell has 8 sacs
Curved like shallow bowl
Membrane supported by protein skeleton (actin, spectrin)
Scaffold linked to motor proteins that direct movement of vesicles into and out of the golgi
What are coatomer protiens
Surface proteins that bind to transmembrane proteins
What is the function of coatamer COP1 and COP2
Assemble on cytosolic surface of donor compartment membranes at sight where binding takes place
Whats the difference between COP-I and COP-II
COP-I moves on retrograde direction
COP-II coated vesicles move in anterograde direction
What is the key function of lysosomes
Digestive organs
Recycling plant in cells
