Ch. 9 Cell Signaling TapTap

Gene Expression

Allowing cells to turn specific genes on or off in response to external cues.

Hydrophilic

(water-loving) molecules cannot cross the lipid-based plasma membrane, so they bind to receptors on the cell surface, which then relay the message into the cell through a cascade of molecular events.

Hydrophobic

(water-fearing) signaling molecules like steroid hormones can pass through the membrane and bind to intracellular receptors located inside the cell, often in the cytoplasm or nucleus.

Cell Surface

Intracellular Receptors

Cell-Surface Receptors