Protein Processing and Targeting

Question 1

Describe regulated secretion of proteins

Answer 1

Proteins are packaged into vesicles and only released when they are required

Question 2

When a protein is targeted to the Golgi, what occurs first?

Answer 2

O-linked glycosylation using glycosyl transferase

Question 3

Describe the stages of making insulin in the body

Answer 3

Preproinsulin is secreted- 3 peptide and a signal sequence
Signal removed to become Proinsulin
C peptide removed to leave A and B peptides attached by disulphide bonds. This is mature insulin.

Question 4

Describe constitutive secretion of proteins

Answer 4

Continuous process where proteins are packaged and released constantly via exocytosis