Final answer:
G-actin forms F-actin by polymerization. Polymerization is favored by ATP binding, while dissociation is favored by ATP hydrolysis. Treadmilling occurs due to differential growth and shrinkage rates at the plus and minus ends.
Step-by-step explanation:
G-actin forms F-actin, which is the filamentous form of actin. The characteristics of G-actin that allow it to form F-actin include:
- Polymerization: G-actin monomers polymerize by binding to ATP (adenosine triphosphate). This binding allows the monomers to join the plus end of the actin polymer.
- Dissociation: G-actin can dissociate from the microfilament when ATP is hydrolyzed to form ADP (adenosine diphosphate). This reduces the binding strength of the monomers in the chain, destabilizing the polymer.
The polymerization and dissociation of G-actin are non-equilibrium processes, and the polar nature of the actin polymer leads to differential growth and shrinkage rates at the plus and minus ends, resulting in treadmilling.