BIO 5406
McGilliard

Reading Assignment:

     Hadley, pp. 338-345, 361-362.
 

Objectives:

     After reviewing your lecture notes and reading assignment, you should be able to:

     1.  Recognize the basic steroid ring structure.
 

          Lecture -- 2/18
          Text -- pg. 340
          Figure -- 15.4
          Structure of cholesterol and steroid hormones

     2.  Contrast the embryological origins of the adrenal cortex and medulla.

          Lecture -- 2/18

          Text -- pg. 338

     3.  Identify the location and major secretory products of the zona glomerulosa,
          zona fasciculata, and zona reticularis of the adrenal cortex.
 
         Lecture -- 2/18

         Text -- pp. 338-340
          Figure -- 15.2
          Zones of the adrenal cortex
          Section of adrenal cortex (low power)
          Zona glomerulosa (low power)
          Zona glomerulosa (high power)
          Zona fasciculata (medium power)
          Zona fasciculata/reticularis (low power)
 
     4.  Outline, in general terms, the pathways involved in the biosynthesis of
          mineralocorticoids, glucocorticoids, androgens, and estrogens.
 

          Lecture -- 2/18, 2/20
          Text -- pp. 340-343
          Figure -- 15.3
 

     5.  Describe the reaction catalyzed by each of the following enzymes and explain the

          significance of these enzymatic steps in determining the biological properties of

          the final product.
          a.  Aromatase.
          b.  Cholesterol esterase.
          c.  17,20-Desmolase.
          d.  11-Hydroxylase.
          e.  17-Hydroxylase.
          f.   18-Hydroxylase.
          g.  21-Hydroxylase.

          Lecture -- 2/18, 2/20

          Text -- pp. 340-344
          Figure -- 15.3

          Steroid hormone biosynthetic pathways

     6.  Identify the following compounds in terms of their roles in adrenal steroid
          biosynthesis as precursor, intermediate, or product:
          a.  Aldosterone.
          b.  Cholesterol.
          c.  Cortisol.
          d.  Dehydroepiandrosterone (DHEA).
          e.  Pregnenolone.
          f.   Progesterone.
 

          Lecture -- 2/18, 2/20
          Text -- pp. 340-343
          Figure -- 15.3
          Table -- 15.2

          Steroid hormone biosythetic pathways

     7.  Discuss the importance of the fetal zone of the adrenal cortex in steroidogenesis

          during pregnancy.
 

          Lecture -- 2/20
          Text -- pg. 340

     8.  Describe the cellular mechanism of action of corticotropin (ACTH) in stimulating

          glucocorticoid biosynthesis.
 

          Lecture -- 2/20
          Text -- pp. 344-345

          Mechanism of ACTH action

     9.  Discuss the following disorders as they relate to adrenal steroid biosynthesis:
          a.  Congenital adrenal hyperplasia.
          b.  Hyperaldosteronism.
 

          Lecture -- 2/20
          Text -- pp. 361-362
          Figure -- 15.22