Thought steel was strong? Think again.

The silk of spiders is one of the strongest materials naturally occurring in nature. Scientists have long been trying to recreate this silk synthetically but have never been able to achieve the desired result, but they've still been pretty close.

How do spiders do it? 

The silk in spiders is produced from the spinneret glands in the abdomen and have different glands to make different silks. Some spiders are able to produce up to eight different silks.

The silk is a naturally occurring polypeptide, polymeric protein from the scleroprotein group (structural proteins). The protein in the silk is fibroin which is comprised of spidroin 1 and 2 but the composition varies depending due to different factors such as diet and species. The monomer amino acid units of spidroin is mainly glycine (42%) and alanine (25%), it also contains other amino acids such as serine, leucine, valine, glutamine and others. Whether spidroin 1 or 2 is made depends on the quantity of proline and tyrosine present.

Alanine                                                                        Glycine
             

Image from: Finomfb                                                               Image from: Wiki

The reason why spider silk is so elastic is because after a repeat of five glycine amino acids the beta-chain twists for 180 degrees, allowing spiders silk to extend up to thirty percent its original length. To find out more about the structure of spiders silk visit the Bristol University site. Spiders silk has been found to be five times stronger than steel for the same diameter.

Can we make it too?

In order to produce spider silk, scientists have genetically modified goats DNA so that they produce milk that contains an extra protein which can then be used to make into spiders silk. The issue here lies with spinning the silk, as it is with difficulty that this is done and unfortunately after spinning the silk, it is not as strong as when created from a spider.





Due to the amazing strength of silk, if we were able to at some point in the future manufacture it, there would be many potential uses. One of the most useful would be bullet-proof vests. However, it is also believed that they could be used to make artificial tendons also. Spider silk is definitely something to look out for in the future.