Concept #1: Lipid Hormone Signaling

Practice: What is the major difference between paracrine and endocrine signaling?

Practice: Upon secretion, a chemical messenger (hormone) binds its receptors on other cells that were nearby. The hormone was secreted in such low concentration that it did not have any effect on distant cells, even though those distant cells had the appropriate receptors. We would best classify this hormone as a(n):

Concept #2: Lipid Hormones Diffuse Through Plasma Membranes

Practice: The main difference between hormones that have intracellular receptors and those that have cell membrane receptors is that the former tend to be _______:

a) Larger.

b) Charged. 

c) Amino acid derivatives.

d) Proteins.

e) Hydrophobic.