SORU: aşağıdaki parçaya göre cevaplayınız
As stressed in the passage, with regard to the production of artificial spider silk, the main problem is ----.
Scientists are exploring ways of producing spider silk
artificially, a process difficult to repeat effectively. A
spider's silk gland is a very efficient chemical factory.
Inside its gland, the spider stores a mixture of liquid
proteins, which it is able to transform into light, strong
fibres. Artificial spider silk could have many applications,
from lightweight and durable packing materials to
parachutes, surgical sutures, and even bullet-proof vests.
Producing it synthetically is a two-part process: scientists
must first manufacture the proteins and then find a way to
form them into superfine threads. They have had success
with the first part, by producing proteins through genetic
modification. Binding proteins into fibres as thin and strong
as spider silk, however, has proved to be a challenge.
Recently, however, a group of German scientists have
attempted to solve that problem by using a device
modelled on a spider's glands. Like the arachnid method,
the proteins are mixed with potassium phosphate, and
then the pH is lowered before pressure is applied as the
mixture flows through tiny channels, hardening and
binding the proteins. So far, researchers have been able
to make fibres of only a fraction of an inch long, but they
hope to be able to produce longer, stronger fibres in the
future.