1. C HAPTER 13 – L IPIDS 13.10 – 13.12 By: Mackenzie Stuck & Carlie Strawser

2. 13.10 W HAT ARE SOME OF THE PHYSIOLOGICAL ROLES OF STEROID HORMONES ? Cholesterol: Starting material for the synthesis of steroid hormones Aliphatic side chain on the D ring is shortened Removal of the six – carbon unit Secondary alcohol group Oxidized to a ketone Progesterone: resulting molecule

3. A DRENOCORTICOID H ORMONES Product of Adrenal Glands “Adjacent to the renal” Two groups Mineralocorticoids Regulates concentration of ions Glucocorticoids Control carbohydrate metabolism “Corticoid” Indicates the secretion is the cortex of the gland

4. E X : M INERALOCORTICOIDS Aldosterone Enhances re-absorption of Na ions in the kidneys Increases the loss of Potassium Controls tissue swelling

5. E X : G LUCOCORTICOIDS Cortisol Increases glucose and glycogen concentrations Expense of other nutrients Cortisone (ketone derivative) Used to treat: Inflammatory diseases Rheumatoid arthritis Bronchial asthma

6. S EX H ORMONES Testosterone (male) Promotes normal growth of the male genital organs Increased testosterone Deep voice Facial and body hair

7. Estradiol Synthesized from testosterone Aromatization of the A ring Regulates cyclic changes in the uterus and ovaries Menstrual cycle Increases the level of Estradiol Luteinizing Hormone (LH) causes Ovulation Prepare uterine lining for fertilization No fertilization = decrease

8. 13.11 W HAT ARE BILE SALTS ? Bile Salts Oxidized products of cholesterol 1 st : cholesterol is oxidized to the trihydroxy derivative 2 nd : end of aliphatic chain is oxidized to the carboxylic acid 3 rd : forms an amide bond with an amino acid Taurine Sports drinks

9. P HYSICAL PROPERTIES OF BILE SALTS Powerful detergents 1 end Strongly hydrophilic Rest of the molecule Largely hydrophobic Can disperse dietary lipids facilitates digestion Similar to the action of soap on dirt Remove bile salts in 2 ways Break down products of cholesterol Solubilize cholesterol

10. 13.12 W HAT ARE PROSTAGLANDINS, T HROMBOXANES, AND L EUKOTRIENS ? Prostaglandins A group of fatty-acid-like substances Discovered in the 1930’s by Kurzrok Leib Ulf Von Euler Named it thinking it came from prostate gland Small amount in both sexes

11. C YCLOOXYGENASE (COX) Catalyzing enzyme in the presence of arachidonic acid synthesized in the body creating prostaglandins Two types COX – 1 PGE2 (Prostaglandin E group) Carbonyl group at the 9 th carbon Lowers blood pressure Used as a decongestant Induces labor

12. COX – 2 Responsible for making prostaglandins Occurs when inflammatory cells interact with resident cells because the tissue is injured

13. T HROMBOXANES A class of arachidonic acid Drived from PGH2 Has a cyclic acetal ring induces platelet aggregation thromboxanes A2 causes blood to clot more NSAI in COX enzymes can cause excessive bleeding

14. THE END !!!!!!!!!!!!