Silk moth caterpillars have been genetically modified so that they make a blend of their own silk and the much stronger spider silk from the golden orb web spider. The spider silk polypeptide chain contains many repeating pairs of the amino acids glycine and alanine, organised into a crystalline structure. What is the correct description of the structure of spider silk?
- Aprimary protein structure with regions of $\alpha$-helices
- Bsecondary protein structure with regions of $\beta$-pleated sheets
- Ctertiary protein structure with regions of $\alpha$-helices
- Dquaternary protein structure with regions of $\beta$-pleated sheets