Question

Which class of hormones can diffuse through plasma membranes?

a) Peptide
b) Steroid
c) Amino acid derivative
d) Proteinaceous

Answer 1

Steroid

Step-by-step explanation:

Steroid hormones are able to diffuse through plasma membranes because they are lipophilic molecules. The plasma membrane is composed of a lipid bilayer, which is impermeable to most hydrophilic molecules, such as peptide hormones and proteinaceous hormones. However, steroid hormones don't have cholesterol and have a structure that allows them to easily pass through the lipid bilayer of the plasma membrane.

Answer 2

Lipid-derived hormones can diffuse through plasma membranes due to their lipid-soluble nature, acting through intracellular receptors, unlike peptide and amino acid-derived hormones which require cell surface receptors.

Step-by-step explanation:

The class of hormones that can diffuse through plasma membranes are lipid-derived hormones, also known as lipid-soluble hormones. Unlike peptide and amino acid-derived hormones, which are lipid insoluble and require cell surface receptors to exert their effects, lipid-derived hormones can permeate the plasma membrane and act through intracellular receptors.

This characteristic allows them to be effective for longer durations within the circulation.