Collagen Synthesis

Question 1

collagen consists of 3 ___ chains to form a ___ ____

Answer 1

3 polypeptide chains to form a triple helix.

Question 2

what are the 3 poly peptide chains that form collagen

Answer 2

2 A1 polypeptide chains

1 A2 polypeptide chain.

Question 3

How is a fibril of collagen formed?

Answer 3

by multiple tropocollagen subunits aligning end to end and then overlapping parallel in a stepwise fashion.

Question 4

a SINGLE triple helix structure of collagen is called ___

Answer 4

procollagen

Question 5

collagen is originally synthesized as _____ on ____ of the rough ER

Answer 5

synthesized as PROCOLLAGEN on ribosomes of the ROUGH ER

Question 6

Where is tropocollagen made?How is it made? What does tropocollagen form?

Answer 6

it is made in the ECM. Procollagen made in the cell by ribosomes is moved to the ECM, where it is CLEAVED and turned into tropocollagen.

Question 7

tropocollagen polymerizes to form ___

Answer 7

FIBRILS

Question 8

Role of procollagen pepsidases

Answer 8

cuts nonhelical ends of Procollagen in the ECM and converts it to tropocollagen

Question 9

role of lysyl oxidase

Answer 9

connects tropocollagen molecules together in the ECM to form a fibrillar structure

Question 10

how does procollagen helix actually get exported into the ECM?

Answer 10

via exocytosis. After being made by the rough ER ribosomes, they move from the cis to trans golgi, and leave the trans golgi in vesicles that get exocytosed.