Lipid-soluble signaling molecules, such as testosterone, cross the membranes of all cells but affect only target cells because
A) only target cells retain the appropriate DNA segments.
B) intracellular receptors are present only in target cells.
C) most cells lack the Y chromosome required.
D) only target cells possess the cytosolic enzymes that transduce the testosterone.
E) only in target cells is testosterone able to initiate the phosphorylation cascade leading to activated transcription factor.

Question

Quizplus · Accepted Answer

Lipid-soluble signaling molecules, such as testosterone, can cross the membranes of all cells, but they only affect target cells because intracellular receptors are present only in target cells. Therefore, only target cells are able to respond to the signaling molecule.

Lipid-Soluble Signaling Molecules, Such as Testosterone, Cross the Membranes of All