Protein Transport Flashcards
What are the different possible destinations of proteins whose synthesis is completed on free ribosomes?
remain in the cytosol/cytoplasm
nucleus
mitochondria
chloroplasts
membranes
cytoskeleton
What are the different possible destinations of proteins that enter the endomembrane system?
ER (rough and smooth)
golgi apparatus
lysosomes
secretion (outside the cell)
plasma membrane
intracellular organelles
How does a protein enter the endomembrane system? What is the role of the enzyme signal peptidase?
protein synthesis starts on free ribosome
SRP binds to signal peptide
SRP binds to translocation complex in ER
SRP leaves - polypeptide chain grows
signal peptide cleaved by signal peptidase
polypeptide released into ER lumen
What tells the protein where to go?
amino acid code
