Question

Part of cortisol’s role in the body involves passing through the plasma membrane to initiate signaling inside a cell. Describe how the structures of cortisol and the plasma membrane allow this to occur.

a) Cortisol is hydrophobic, allowing it to pass through the lipid bilayer
b) Cortisol is hydrophilic, allowing it to dissolve in the cytoplasm
c) Plasma membrane excludes cortisol entry
d) Cortisol and plasma membrane lack structural compatibility

Answer 1

Cortisol is a hydrophobic steroid hormone that can pass through the plasma membrane due to its structural compatibility with the hydrophobic lipid core of the membrane.

Step-by-step explanation:

Cortisol is a hydrophobic steroid hormone that is able to pass through the plasma membrane. The plasma membrane is constructed of a phospholipid bilayer, with hydrophilic heads facing outward and hydrophobic tails facing inward. Because cortisol is hydrophobic, it is able to dissolve in the hydrophobic lipid core of the plasma membrane and pass through the membrane to initiate signaling inside the cell.