Chemotaxis is a process by which cells migrate toward higher concentrations of a signaling molecule. The signaling binds cell-surface receptors that result in actin polymerization at the cell membrane. Actin polymerization results in the formulation of filamentous actin that exerts a force and leads to protrusion of the leading edge. A researcher tested Compound A on chemotaxing cells and measured the relative amount of filamentous actin found in the cells at different times. Part D. The researcher hypothesizes that Compound A passively diffuses through the cell membrane to bind actin subunits. Which of these observations, if true, would MOST support his hypothesis? Increasing extracellular sodium concentration interferes with Compound A function, adding actin to the extracellular medium interferes with Compound A function, reducing the temperature of the cell interferes with Compound A function, or blocking ATP hydrolysis interferes with actin function.
