If a solute is moving through a phospholipid bilayer from an area of higher concentration to an area of lower concentration without the assistance of a protein, the manner of transport must be
a. active transport
b. facilitated diffusion
c. simple diffusion
d. any of the above, depending on the solute
e. solutes cannot cross phospholipid bilayers.

Ras is a g-protein that is activated when a growth factor attaches to egfr. its activation results in the replacement of a gdp molecule with a gtp molecule, thus allowing a signal transduction pathway to be activated. considering the signal pathway illustrated on this page, what is one potential outcome of a mutation in the ras gene that leads to ras protein hyperactivity. be specific.