12 Questions
How many types of collagen have been identified in vertebrates?
28
What is the function of lysyl oxidases (LOX) in collagen synthesis?
Covalent crosslinking between lysine residues
What is the role of cell contraction in FN-fibril assembly?
It promotes FN-fibril assembly
What is the function of fibrous collagens?
They form the backbone of the collagen fibril bundles
How is fibronectin secreted?
As a dimer
What is the result of the cleavage of N- and C-terminal propeptides in collagen synthesis?
The formation of fibrils and networks
Fibronectin is secreted as a monomer joined by a single C-terminal disulfide bond.
False
The majority of collagen molecules form a double-stranded helix.
False
Network collagens are incorporated into the interstitial tissue stroma.
False
Glycosylation of proline residues is a post-translational modification involved in collagen type I synthesis.
False
The binding of fibronectin to heparin is not essential for its assembly into longer fibrils.
False
Collagen fibrils are strengthened by the covalent crosslinking between proline residues of the constituent collagen molecules.
False
Study Notes
Collagen Synthesis
- 28 types of collagen have been identified in vertebrates
- Collagen molecules form a triple-stranded helix, which can assemble into supramolecular complexes like fibrils and networks
- Fibrous collagens form the backbone of collagen fibril bundles in interstitial tissue stroma
- Network collagens are incorporated into the basal membrane (BM)
Post-Translational Modifications in Collagen Synthesis
- Synthesis of collagen type I involves enzymatic post-translational modifications
- Modifications include hydroxylation of proline and lysine residues, glycosylation of lysine, and cleavage of N- and C-terminal propeptides
Collagen Fibril Formation
- Collagen fibrils are strengthened by covalent crosslinking between lysine residues of constituent collagen molecules by lysyl oxidases (LOX)
Fibronectin Synthesis and Assembly
- Fibronectin (FN) is secreted as a dimer joined by two C-terminal disulfide bonds
- FN has binding sites for other FN dimers, collagen, heparin, and cell-surface integrin receptors
- Cell-surface binding of soluble FN dimer is essential for its assembly into longer fibrils
- Cell contraction through the actomyosin cytoskeleton and integrin clustering promotes FN–fibril assembly
Collagen Synthesis
- 28 types of collagen have been identified in vertebrates
- Collagen molecules form a triple-stranded helix, which can assemble into supramolecular complexes like fibrils and networks
- Fibrous collagens form the backbone of collagen fibril bundles in interstitial tissue stroma
- Network collagens are incorporated into the basal membrane (BM)
Post-Translational Modifications in Collagen Synthesis
- Synthesis of collagen type I involves enzymatic post-translational modifications
- Modifications include hydroxylation of proline and lysine residues, glycosylation of lysine, and cleavage of N- and C-terminal propeptides
Collagen Fibril Formation
- Collagen fibrils are strengthened by covalent crosslinking between lysine residues of constituent collagen molecules by lysyl oxidases (LOX)
Fibronectin Synthesis and Assembly
- Fibronectin (FN) is secreted as a dimer joined by two C-terminal disulfide bonds
- FN has binding sites for other FN dimers, collagen, heparin, and cell-surface integrin receptors
- Cell-surface binding of soluble FN dimer is essential for its assembly into longer fibrils
- Cell contraction through the actomyosin cytoskeleton and integrin clustering promotes FN–fibril assembly
This quiz covers the synthesis of collagen and fibronectin, including the different types of collagen and their functions in the human body.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
