KERATIN vs COLLAGEN Flashcards
What does keratin do?
Provide structural integrity to hair, skin and nails
What type of molecules make up keratin?
a helical
How many residues per turn are there in a keratin molecule?
3.5 (1st and 4th hydrophobic)
What are the hydrophobic amino acids in a keratin molecule?
Glycine, cysteine and proline
What do cysteines form?
Disulphide bonds between keratin dimers
What holds keratin helices together?
Disulphide bonds and weak hydrophobic interactions
What does collagen do?
Provides strength and elasticity to bones, skin, connective tissues
What amino acids are present in a collagen molecule ?
- glycine
- proline
- hydroxyproline
- hydroxilysine
How many structures does collagen have?
Two - primary and secondary
What does the primary structure of collagen consist of?
Regions with repeated tripeptides (gly- X - Y)
At what position does glycine appear in on the tripeptide?
Every third position
What does the secondary structure of collagen consist of?
Polyproline type II helix on each chain and a repetition of proline residues
How many residues does a polyproline type II helix have on a collagen molecule?
3
What are the two types of collagen?
I and IV
What is type I collagen?
90% of body collagen, densely packed and providing structure
