Biochemistry 3386B Lecture 3: Deroo Lecture 3 Notes
4 Feb 2015
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Document Summary
Iden-fy the major classes of steroid hormones. Describe how these steroid classes are synthesized. Learn where steroids are synthesized in your body and what they do. Describe the di erent enzyma-c reac-ons that are involved in steroidogenesis. What is a steroid hormone: a class of lipids, steroids that act as hormones, a mafer of terminology steroid skeleton eg. cholesterol. Five key classes of steroid hormones loca>on of synthesis. Steroid class adrenal cortex glucocor-coids mineralocor-coids adrenal cortex androgens estrogens progestogens testes & adrenal cortex ovaries & placenta ovaries & placenta. Loca>on of steroid hormone produc>on progestogens estrogens glucocor-coids mineralocor-coids androgens androgens progestogens estrogens. Di erent classes of steroidogenic enzymes: oxidoreductases (eg. 3- - hydroxysteroid dehydrogenase) Cyp17a1 has both 17alpha- hydroxylase and 17,20- lyase ac-vi-es. Addi-on of a hydroxyl group (hydroxylase): acts on pregnenolone and progesterone. Acts upon 17- hydroxyprogesterone and 17- hydroxypregnenolone to split the side- chain o the steroid nucleus (the lyase ac-vity) reductase (5 - reductase)
