🔬 Biology · Locomotion and Movement · NEET

Which protein forms the thin filaments in muscle?

Answer: Actin.

A Myosin
B Collagen
C Actin
D Keratin

Correct answer: C. Actin

Explanation: Actin forms the thin filaments. The thin filament also contains tropomyosin (blocks myosin binding sites at rest) and troponin (Ca<sup>2+</sup> sensor that moves tropomyosin to expose binding sites).

Structure of a sarcomere showing thick myosin filaments and thin actin filaments with the Z line, M line, A band, I band and H zone labelled

A sarcomere (Z line to Z line): during contraction the I band and H zone shorten as thin filaments slide over thick, while the A band stays the same length. Image: SlothMcCarty, CC BY-SA 3.0, via Wikimedia Commons.

Concept context

Types of movement, muscle contraction, skeletal system, joints, and disorders. Important for Class 11 and NEET.

Read the full Locomotion and Movement notes →

Which protein forms the thin filaments in muscle?

Concept context

More Locomotion and Movement questions