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Percentage composition of fibroin and sericin in silk is:
A) 50:40
B) 80:20
C) 30:70
D) 40:60

Last updated date: 21st Jul 2024
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Hint:Silk is a natural protein fiber, a few types of which can be woven into textiles. The protein fiber of silk is made up of fibroin and sericin which are obtained by certain insect larvae to form cocoons. The most popular silk is obtained from the cocoons of the larvae of the mulberry silkworm Bombyx mori raised in Sericulture.

Complete answer:
Silk is produced by insects; but, for the most part, just the silk of moth caterpillars has been utilized for textile assembling and manufacturing. It comprises mostly two proteins, fibroin and sericin. Silk comprises 70–80% fibroin and 20–30% sericin; fibroin being the basic focal point of the silk, and sericin being the gum covering the strands and permitting them to adhere to one another.
Fibroin is an insoluble protein present in silk created by various silkworms, for example, the Bombyx mori, and other moth genera, for example, Antheraea, Cricula, Samia and Gonometa. Sericin is a protein made by Bombyx mori (silkworms) in the creation of silk.

Fibroin is secreted in the Posterior and moved by peristalsis to the Middle segment, which goes about as a supply. Here it is put away as a thick fluid arrangement until needed for spinning. Most of the sericin is made inside the walls of the Middle area. Indeed, these two proteins are saved one next to the other in the Middle segment without blending one into the other. The fibroin center is covered with a layer of sericin and the emissions from the two proteins join at the intersections where the sericin is melded into one layer. The Filipis organs release a fluid protein. To form its cocoon, the silkworm draws out the string of fluid protein and inside adds layer after layer to finish this defensive covering.

Hence, the correct answer for this question is option B, i.e. 80:20

Note:Natural silk is one of the most grounded material strands, and this can be represented by the stretched out molecular structure. Silk (78% protein) is a lot stiffer than fleece disregarding both being proteins produced using amino acids chains. Silk filaments have fine hanging characteristics and are normally crease resistant and bring a warm feel.