Chapter 14, Problem 14.6PS

(a)

Summary Introduction

To explain: The orientation of actin and myosin in stress fibers present in nonmuscle cells.

Introduction: Stress fibers present in nonmuscle cells are contractile in nature and are composed of actin and myosin II. Myosin II is a major component for the contraction of stress fibers in nonmuscle cells. Myosin fibers are ATP dependent and hydrolysis of ATP can bring a significant change in the conformation of myosin fibers resulting in the movement of actin filaments.

(b)

Summary Introduction

To explain: The ability of role of fibroblasts to wrinkle the rubber would change if treated with a permeable form of C3 transferase that modifies an amino acid present in Rho.

Introduction: Rho protein plays a major role in the activation of stress fibers. Stress fibers present in nonmuscle cells are contractile in nature and are composed of actin and myosin II. Myosin II is a major component for the contraction of stress fibers in nonmuscle cells.

(c)

Summary Introduction

To understand: The activity of active Rho in the fibroblasts.

Introduction: Rho protein plays a major role in the activation of stress fibers. Stress fibers present in nonmuscle cells are contractile in nature and are composed of actin and myosin II. Myosin II is a major component for the contraction of stress fibers in nonmuscle cells.