Biology 52: Problem Set for Lectures 3 and 4
1. The gecko is a reptile that has the amazing ability to climb smooth surfaces -
even glass. Recent discoveries indicate that geckos stick to smooth surfaces via
van der Waals interactions between septae on their feet and the smooth surface.
2. Below is a standard table of the amino acids, and the sequences of a short
polypeptide that has one transmembrane domain.
D acidic A nonpolar
E acidic G nonpolar
R basic V nonpolar
K basic L nonpolar
H basic I nonpolar
N polar P nonpolar
Q polar F nonpolar
S polar M nonpolar
T polar W nonpolar
Y polar C nonpolar
MKRENDSDNHIALVVLSWLAIEGGLTAFFGFEDNIKELDNK
Underline the predicted transmembrane domain in the polypeptide above.
When not selling car insurance, geckos have
climb smooth surfaces.
(a) How is this method of stickiness
advantageous to the gecko over covalent
interactions?
(b) Given that van der Waals forces are
among the weakest molecular interactions,
how can the gecko's feet stick so
effectively?
