Unit 1 - Topic 2 - Proteins - Section B - The synthesis and transport of proteins - Part IV - The secretory pathway

Question 1

Where are secreted proteins translated

Answer 1

Secreted proteins are translated in ribosomes
on the RER and enter its lumen

Question 2

Examples of secreted proteins

Answer 2

Peptide hormones and digestive enzymes

Question 3

Where do the proteins go and what happens to them after this

Answer 3

The proteins move through the Golgi apparatus and are then packaged into secretory vesicles

Question 4

These vesicles move to and fuse with the and what does it release

Answer 4

These vesicles move to and fuse with the plasma membrane, releasing the proteins out of the cell

Question 5

What are many secreted proteins synthesised as

Answer 5

Many secreted proteins are synthesised as inactive precursors and require proteolytic cleavage to produce active proteins

Question 6

What is proteolytic cleavage and what are digestive enzymes an example of

Answer 6

Another type of post-translational modification. Digestive enzymes are one example of secreted proteins that require proteolytic cleavage to become active.