Question

A fibrous protein present in muscles is:

• A. keratin
• B. albumin
• C. riboflavin
• D. insulin
• E. myosin

Hint:

Fibrous proteins like myosin are critical for muscle movement, while globular proteins like albumin have more varied roles in the body.

Answer 1

Answer: (E)

Fibrous proteins are structural proteins that typically have a long, thread-like shape. They are insoluble in water and provide support and strength to cells and tissues. 
Among the given options: 
- Keratin is a fibrous protein found in hair, nails, and the outer layer of skin, not specifically in muscles.
- Albumin is a globular protein found in blood plasma and is involved in maintaining osmotic pressure, not in muscle structure.
- Riboflavin is a vitamin (B2) and not a protein.
- Insulin is a globular protein involved in regulating blood glucose levels, not a structural protein in muscles. 
The correct answer is myosin, a fibrous protein found in muscle cells. It is a motor protein that plays a key role in muscle contraction. 
Thus, the correct answer is \( \boxed{{Myosin}} \), corresponding to option (E)