Animal Hormones

1 peptides or proteins groups of hormones hormones

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: oups: ! 1) Peptides or proteins Groups of Hormones • Hormones can be classified into three main groups: ! 2) Steroid hormones " Are water soluble and transported by vesicles out of the cell that made them. " Peptide hormone receptors are localized in the surface of target cells. " 41 Are lipid-soluble and membrane-permeable " Can diffuse out of the cell that made them. " Can diffuse into the target cells. " In the blood they must be bound to carrier proteins. " The receptors for lipid-soluble hormones are inside cells, either in the cytoplasm or in the nucleus. " Examples:
 Growth hormone,
 insulin " Example: Estrogen Insulin 19 20 Figure 42.11 The Corticosteroid Hormones are Built from Cholesterol 41 Groups of Hormones • Hormones can be classified into three main groups: ! 3) Amine hormones " " Example: epinephrine/adrenaline 22 Figure 15.4 Two Locations for Receptors 41 Nonpolar hormone Some are water-soluble and some are lipid-soluble. " 21 Are derivatives of the amino acid tyrosine. Polar hormone Receptors for polypeptide hormones • The receptors for water-soluble proteins are large glycoproteins on the cell surface with three domains: ! A binding domain projecting outside the plasma membrane ! A transmembrane domain that anchors the receptor in the membrane ! A cytoplasmic domain that extends into the cytoplasm of the cell • The cytoplasmic domain initiates the target cell’s response by activating enzymes such as protein kinases or protein phosphatases. 23 24 41 The insulin receptor 41 Receptors for membrane-permeable Hormones • The receptors for lipid-soluble hormones are inside cells, either in the cytoplasm or in the nucleus. • The action of lipid-soluble hormones is mediated by intracellular hormone receptors that usually alter gene expression. 25 41 The estrogen receptor 26 41 Endocrine glands • Some endocrine cells are single cells within a tissue. • Digestive hormones, for example, are secreted by isolated endocrine cells in the wall of the stomach and small intestine (examples: Gastrin, Secretin,...
View Full Document

This note was uploaded on 02/13/2014 for the course MCDB 1B taught by Professor Weimbs during the Winter '08 term at UCSB.

Ask a homework question - tutors are online