U3A1: 2F: the protein secretory pathway

Question 1

organelles involved in exocytosis

Answer 1

• ribosomes
• rough endoplasmic reticulum
• transport vesicles
• golgi apparatus
• secretory vesicles

Question 2

first stage of exocytosis

Answer 2

proteins produced at ribosomes are folded in the RER and transported via transport vesicles to Golgi apparatus. here they are modified and packaged into secretory vesicles which are transported to the plasma membrane.

Question 3

second stage of exocytosis

Answer 3

a membrane of the secretory vesicle fuses with the cell plasma membrane.

Question 4

third stage of exocytosis

Answer 4

the secretory products are released from the cell into the extracellular environment.