[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Are dinosaurs really reptiles? (2)

Martin Baeker writes: 

Just a minor note: AFAIK, in general beta-Keratin is stiffer (larger
young's modulus, about 5-8GPa, compared to 2-3GPa or so for
alpha-Keratin) than alpha-Keratin due to the beta-structure (if you
strain it, you strain the covalent bonds along the backbone chain of
the molecule, whereas in alpha-keratin you start by straining the
hydrogen bonds along the helix.)

I believe beta-keratin is also more waterproof. Reptiles need a good waterproof skin to stop from drying out, whereas us mammals with our gross sweaty glandular skin require something a bit more water permeable.


___________________________________________________________________ 

Dann Pigdon
GIS / Archaeologist              http://geo_cities.com/dannsdinosaurs
Melbourne, Australia             http://heretichides.soffiles.com
___________________________________________________________________