- Exam
- NEET
- Subject
- Zoology
- Chapter
- Locomotion and Movement
NEET · Zoology · Locomotion and Movement
How is troponin distributed on the tropomyosin?
Options
- AIrregularly
- BIn a random pattern
- CAt regular intervals
- DOnly at the ends of the tropomyosin
Correct answer
C. At regular intervals
Step-by-step solution
The striated appearance of myofibrils is due to the distribution pattern of two important proteins - Actin and Myosin. The light bands contain actin and the dark bands contain myosin.The light bands in a myofibril contain actin and is called I-band or Isotropic bandThe actin filaments are thinner as compared to the myosin filaments Each actin (thin) filament is made of two "F" (filamentous) actins helically wound to each other.Each "F" actin is a polymer of monomeric "G" (Globular) actinsTwo filaments of another protein, tropomyosin also run close to the "F" actins throughout its length.In the resting state a subunit of troponin masks the active binding sites for myosin on the actin filaments.Troponin is distributed at regular intervals on the tropomyosin.