Fibrous Proteins Flashcards
What are fibrous proteins?
-long stands of polypeptide chains - have cross linkages due to H bonds
-no tertiary structure
-limited no.of amino acids - highly repetitive sequence
Examples of fibrous proteins
-keratin
-elastin
-collagen
What is collagen?
-most common structural protein found in vertebrates
-provides structural support
-forms tendons, cartilage, skin and the walls of blood vessels
What is the structure of collagen?
-formed from 3 polypeptides chains held together by H bonds = triple helix
-each chain is a helix shape - contains amino acids
-PS = every 3rd amino acid is glycine
What are the functions of collagen?
-flexible structural protein
-forming connective tissues
-lots of H bonds = great tensile strength
-stable protein
-length of collagen molecule = too long to dissolve in water (insoluble)
What is keratin?
-found in hair + fingernails
-strong and soluble in water
-high proportion of cysteine = strong
What is elastin?
-skin, walls of arteries
-long cross linked strands - containing hydrophobic regions
-when stretched - spring back together