What Property of Steroid Hormones Allows Them to Cross the Phospholipid

Question

What property of steroid hormones allows them to cross the phospholipid bilayer?
A)Steroid hormones are lipid soluble and easily cross the phospholipid bilayer.
B)Steroid hormones can act in very small concentrations and very few molecules of steroids need to cross the lipid bilayer.
C)Steroid hormones act on cells close to where they were produced and very few molecules are required to travel such a short distance to cross the lipid bilayer.
D)Steroid hormones act on the same cells in which they are produced and, therefore, are within the cell they are acting upon.
E)Cells have protein carriers for steroids in their plasma membranes so the steroid can be transported to the cytoplasm.

Accepted Answer

Steroid hormones are lipid soluble, hydrophobic molecules that are able to easily diffuse across the phospholipid bilayer without the need for a carrier protein. This is due to their molecular structure, which includes a nonpolar region that allows them to dissolve in the nonpolar interior of the lipid bilayer. This property makes steroid hormones different from many other signaling molecules, such as proteins and peptides, which are hydrophilic and need a receptor on the cell surface to activate intracellular signaling pathways.