Connective Tissue Flashcards
Reticular Fibers
Composed of type III collagen
Branched thin fibers
Highly glycosylated
Where is type I collagen found?
Skin, Bone, Tendons
Where is type II collagen found?
Carilage
Where is type III collagen found?
Reticular fibers, various organs and blood vessels
Where is type IV collagen found?
Basement membrane
Structure of alpha collagen chains
Gly-X-Y
X often proline
Y often hydroxyproline
Compared to normal collagen, lack of hydroxyproline has what effect?
Lowers melting point
Vitamin C (ascorbate) is necessary for collagen because ______
Ascorbate is important cofactor of prolyl hydroxylase
Where and by what are the procollagen chains of collagen cleaved?
Occurs in the extracellular space by procollagen peptidase
Collagen fibers are put together into fibril by?
Lysyl Oxidase: cross links lysine with hydroxylysine
T or F collagen fibrils contian multiple collagen types?
True: important for interactions with ECM components
Elastic Fibers
Formed by polymerization of elastin molecules
Contains fibrilin
Elastin molecules linked together by lysyl oxidase
Difference between elastic and collagenous fibers
Elastic fibers lack a lot of hydroxyproline
Elastic fibers give flexability while collagen fibers give structural support
Glycosaminoglycans (GAG)
Repeating disaccharide structure
Found in: synovial fluid, vitreous humor and cartilage
Proteoglycans
Very large, negatively charged molecules
Bind to growth factors
Form hydrated, space filling gels that resist compression.
