ch 9 Flashcards
endoplasmic reticulum, golgi, lysosome
endoplasmic reticulum
membrane continuous with nuclear membrane
lumen
liquid inside membrane
rough ER
coated with ribosomes
synthesizes proteins
smooth ER
free of ribosomes
synthesizes lipids
how do ribosomes get to the ER
- signal sequence gets bound by SRP
- SRP stops translation and carries ribosome to rough ER
- SRP binds SRP receptor in ER membrane
define signal sequence
amino acids at the end of a new polypeptide
define SRP
signal recognition particle
protein complex
define SRP receptor
protein that anchors SRP and ribosome to ER
translocon
channel that ribosome feeds growing polypeptide through
chaperone function in ER
bind to proteins that enter ER lumen and help them fold
transmembrane proteins
proteins embedded in membrane
not fully fed into the lumen
how are proteins embedded in the membrane
translocating polypeptide is moved laterally from translocon to membrane
polypeptide is passed through lateral gate
multi-pass proteins
proteins that cross the membrane more than once
where are phospholipids synthesized
membrane of smooth ER
flipases
enzymes that flip phospholipids to other side of bilayer
golgi function
sort, package, modifying, transporting molecules
cis face of golgi
faces the ER
vesicles with proteins enter
medial region of golgi
middle stacks
proteins flow through and get modified
trans face of golgi
faces other regions of cells
vesicles go to membrane or other organelles
glycosylated
carbohydrates are covalently attached to proteins
helps control where proteins go next
T/F: glycosylated proteins are sorted into different regions of the trans golgi
true
vesicle
small membrane-bound spheres within the cell
transports contents
steps of vesicle transport
- protein cargo loaded at vesicle region
- vesicle takes shape with help of coat proteins
- vesicle is pinched off
- vesicle carried along cytoskeleton
- vesicle fuses with target membrane
coat proteins
surround vesicle region and help it form a sphere
