Protein Trafficking

Question 0

Two major places proteins end up

Answer 0

• Secretes

- incorporated into plasma membrane

Question 1

Where are proteins synthesized

Answer 1

Ribosomes

Question 2

Signal peptide

Answer 2

• mino acid sequence at the end of the peptide that is recognized by a “signal recognition particle”
• if it has this peptide the signal recognition particle binds to the signal peptide and translation is halted
• the signal recognition particle take the entire thing over the rough ER

Question 3

Once it is implanted into the rough ER

Answer 3

• it threads the peptide through the membrane into the ER lumen
• translation begins again and the rest of the protein is translated
• if the protein is destined for secretion the entire peptide will end up in rough ER
• if destined to be an integral membrane protein it is inserted into the membrane
• they then bud off in vesicles to the golgi

Question 4

At the golgi

Answer 4

From the rough ER it goes to the golgi
-proteins that are to bes ecreted are completely within a vesicle
-proteins for membrane are just threaded into vesicle
Cis side
Trans side

Question 5

Proteins headed for membrane

Answer 5

Vesicle fuses with the membrane