Quiz for Lecture 2:
Scientists believe there are at least two reasons why spiders don't stick to their webs.
First, some spiders have oil on their bodies. The oil is slippery, so the web won't stick to
it. Second, since spiders build their own webs, they know which strands of silk are sticky
and which ones are not. They stay away from the sticky strands.
Spider silk cannot be dissolved in water and is the strongest natural fiber known.
Tirrell reports that the primary constituents of spider silk turn out to be the two simplest
amino acids, glycine and alanine, and he notes that researchers at Cornell have recently
discovered that the alignment of these amino acids is responsible for spider silk's
incredible strength.
1) Think about what you have read. Why do you think spider silk will not dissolve in
water?
2) Why are the amino acids in spider silk of importance? Do a small bit of research on
your own and come up with a plausible explanation.
(Hint) Why wouldn’t spider silk adhere to an oily surface?