Question

Skeletal muscles appear striated due to presence of two characteristic proteins in alternating dark and light bands. Which of the following is a correct match of the protein with its light refractive property and colour?

• A. Protein : Myosin, Colour : Light, Property : Anisotropic
• B. Protein : Actin, Colour : Dark, Property : Anisotropic
• C. Protein : Myosin, Colour : Dark, Property : Isotropic
• D. Protein : Actin, Colour : Light, Property : Isotropic

Answer 1

The correct option is D Protein : Actin, Colour : Light, Property : Isotropic

Each actin (thin) filament is a polymerised protein made up of two 'F' (fibrous) actin strands helically wound to each other. Each "F" actin is a polymer of monomeric "G" (globular) actins. It is light in colour and shows isotropic property.