Session 10 (Collagen And Insulin) Flashcards
What is the basic structure of tropocollagen?
RH triple helix, 3rd glycine amino, 3 alpha polypeptides, rod shaped
Where might you find each type of collagen? (5)
Type 1- (common)skin, tendon, ligaments, bone 2- cartilage, intervertebral discs 3- foetal skin, cardiovascular system IV- basement membrane 5- placenta, skin
How and where does pre-procollagen become procollagen?
In the ER, signalling sequence is cleaved by signal peptidases
What residues might be hydroxylated in the collagen structure?
Proline + lysine
Become so hydroxyproline etc
Where do the disulphide bonds form in procollagen?
C terminus
What is a N-linked oligosaccharide?
Sugar molecules added to the amine group of amino acids
What part of the structure of procollagen does not form the helix?
N and C terminus
Where is O-linked oligosaccharide occuring?
Golgi Apparatus
How does procollagen leave fibroblasts?
By transport vesicles (constitutive secretion)
What is removed to produce tropocollagen from procollagen?
N and C terminals
What enzyme makes covalent cross links between molecules of tropocollagen?
Lysl oxidase
How would you increase the stability of a collagen fibre?
Add hydroxyl group onto amino acids which would result in more H bonds
Name the intermediates from preprocollagen to collagen fibres (5)
Preprocollagen (ER) Procollagen (GA) Tropocollagen (EXC) Collagen fibrils Collagen fibres
