Intracellular transport

Question 1

gated transport - cytosol and nucleus

Answer 1

nuclear import and export

Question 2

transmembrane transport

Answer 2

proteins move through translocators, across a membrane from cytosol to organelle

Question 3

vesicular transport

Answer 3

membrane bound transport intermediates

Question 4

functions of ER

Answer 4

synthesis of lipids (phospholipid, ceramide, cholesterol), control of cholesterol homeostasis (sensor and synthesis), synthesis of proteins on membrane bound ribosomes, Co-translational folding of proteins and early post-translational modifications, quality control (checks for proper folding)

Question 5

co-translational translocation

Answer 5

transcribing protein has signal seq that associates wih ER, signal receptor particle (SRP) binds to this area, stops transcription of protein until SRP binds to SRP receptor in ER, ribosome binds to translocon on ER, protein is threaded through the translocon and ends up properly folded

Question 6

functions of Golgi

Answer 6

synthesis of complex sphingolipids from ceramide backbone, post-translational mods to proteins and lipids (i.e. sulfation, glycosylation), proteolytic processing, sorting of proteins and lipids for post-golgi compartments

Question 7

3 well-studied vesicle coats

Answer 7

COPI (ER to Golgi), COPII (Golgi to ER), Clathrin (Golgi to membrane, membrane to lysosome, all over the place).

Question 8

vesicle coats and function

Answer 8

coats assemble at sites of vesicle formation from soluble cytoplasmic components and sort molecules to be moved forward or backward, coat formation assist in physical deformation of planar membrane.