Question

Which of the following describes the structure of an actin filament?

A. It is a hollow cylinder made up of actin molecules.
B. It is a double helix made of actin molecules.
C. It is a structure with a long tail and two globular heads.
D. It is a branched network of actin monomers.

Answer 1

Actin filaments are composed of two intertwined strands of actin that form a double helix, essential for muscle contraction and various cellular functions. Option number b is correct.

Step-by-step explanation:

Among the options given for describing the structure of an actin filament, the correct description is that it is a double helix made of actin molecules (Option B). Microfilaments, also known as actin filaments, are composed of two intertwined strands of actin.

These actin monomers polymerize to form filamentous cables typically around 6 nm in diameter, which are then twisted around each other to form a double helix. This structure is crucial for various cellular processes, including muscle contraction, where the interaction between actin and myosin proteins allows cells to contract.