Fibrous Proteins: Flashcards
What do fibrous proteins role often play?
= play as a structural role
What is the structure of fibrous proteins?
= form long, rope-like molecules
= large porportion of amino acids with hydrophobic R groups
Are fibrous proteins insoluable or soluable?
= insoluable
= (hydrophobic R groups)
What is collagen proteins?
= tendons and ligaments
= skin
=
Why is collagen a strong molecule?
= due to structure
= polypeptide chain wrap tightly together to form a triple helix
= ever 3rd amino acid is glycine, r group is a hydrogen atom
= has the smallest r group out of any amino acid
= allows polypeptides to tighly wrap
As the polypeptide wrap around eachother what happens?
= large number of hydrogen bonds form between the polypeptide chains
= help stabalise the quaternary structure
How else are the polypeptide chains joined together?
= by strong cross links
What happens when a large amount of these triple helical molecules join together?
= forms a large structure
= microfibrils
= fibrils
= molecules are staggered (NO WEAK SPOTS)
=
What protein is Keratin?
= found in hair and fingernails
=outer surface of the skin
What are the properties of keratin?
= strong
= insoluable in water
What is the structure of Keratin?
= long stranded molecules
= high porpotion of the amino acide cysteine- has disulfide bonds
What protein is elastin?
= skin contains it= skin supple and elastic
= walls of arterires stretch when blood pulses and recoils in between
=
What is the structure of elastin?
= long strands containing hydrophobic regions
= cross-linked
= normally the hydrophobic regions on different strands associate causing the elastin molecules to join together
When stretched what is the structure of elastin ?
= strands move apart
= remain attached at cross links
= after stretching: elastin molecules reassosciate, springing back together
=
