IPHY 4440 1st Edition Lecture 4Outline of Last Lecture I. Equilibrium chemical reactionsOutline of Current Lecture II. Hormones transport in blood III. Removal of bioregulatorsIV. Life of bioregulatorsV. Chemistry and physiology of bioregulatorsVI. Steroid hormones Current LectureI. Hormone transport in bloodA. Hormones get dumped into blood and bind to plasma proteins= binding proteinsB. Equilibrium reaction between occupied binding proteins and free bioregulators1) If binding protein is occupied  free bioregulator and vice versa (free bioregulator  binds to protein if unoccupied C. Equilibrium reaction between the free bioregulators and receptor on target cell1) Free bioregulator  receptor on target cell (or) receptor on cell matches bioregulator  binds free bioregulatorD. Less active free bioregulators get metabolized and excreted1) Won’t have biological effect unless it’s binded to those plasma proteinsE. Binding proteins have an inert reservoir of hormone meaning that there ample amount of hormone in the body that the hormones kind of just stay in this dormant state in blood until they are needed 1) Ex: if the thyroid gland was removed, there would still be lots of thyroid hormones in the blood because there are a large reservoir for those hormones in the blood bound in that inert state II. Removal of bioregulatorsWant to turn off the signal when necessary A. Metabolize: prevents binding to receptor and enhances excretion B. Where does this metabolism happen?1) Liver enzymes2) Plasma EnzymesThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.3) Target tissuesC. How are they metabolized in those three areas?1) Enzymatic degradation: Proteins, Peptides  Amino acids (Can cleave off oneamino acid at a time)2) Enzymatic inactivation by conversion to a different chemical nature and how they react with receptors. This conversion happens in: biogenic amines3) Conjugation “pairing up,” converting to water soluble forms, make them more excretable, adding a group or important structure to the hormone Ex: steroids and thyroid hormones 4) Hormone’s metabolism has two fates: 1) can become more active or 2) inactivated by either conjugation or enzymatic degradation 5) Hormones are excreted through the liver and kidney. Additionally, through tears, saliva, and sweat for alternate routes for elimination D. Life of a bioregulatorBegins in an endocrine cell  synthesis  release  transport and interaction with target cell  metabolism and/or secretionWhy are bioregulators so complicated? Increase levels of regulation, increase feedback responses, increase sites for disruption (negative effect) because things can go wrong when there are disruptions Key point: bioregulators can have different effects coming out of a certain target cell depending on which receptors are stimulated Clicker Question: Hormones may release at very low levels. What could you do to allow this low level of hormone to become more biologically effective? Answer: increase the number of hormone receptors for up-regulation or down-regulationIII. Steroid hormones* The groups of steroids are based on functions and number of carbons A. Have a steroid nucleus 1) A 4 ring structure  cyclopentanoperhyrophenanthrene ring 2) Rings are lettered and carbons are numbered B. Stereoisomers1) Asymmetric carbons: 3, 5, 11, 17 2) Alpha= “away from you” represented by a dotted line - - - OH3) Beta= “toward you” represented by a solid line4) Estradiol: Most important estrogen in the body that has 2 groups of OH (17a-Estradiol) - Has an aromatic ring so alternate between moving double bonds around the ring (don’t include the OH that is bonded on 3rd carbon) 5) Estrogens (feminizing) have C18 a. Estradiol (E2)= have 2 hydroxy groups OHb. Estriol (E3)= 3 hydroxy groups c. Estrone (E1)= 1 hydroxy group 6) Androgens (masculinizing) have C197) Progestogens: gestational phase, helps in pregnancy maintenance* Progestogens: most important group, have a methyl group at C218) Corticosteroids: (corticoids) C21* Produced from cortex of adrenal gland  adrenal cortex* “Cortex”= outside9) Glucocorticoids: important for stress responses  molecules that produce more glucose10) Mineralocorticoids: regulating sodium and potassium levels in the blood 11) Vitamin D3 (C) 27= calcium absorption in intestines12) Selective estrogen receptor modulators (SERMs)= aka “anti-estrogens”*Blocks estrogens from binding so they occupy the receptor so nothing else can bind especially estrogen. Beneficial for bone mass but essential for cancer (breast/uterus