It would not cause all of these problems what are the

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Unformatted text preview: level is not even that high, in reality. It would not cause all of these problems What are the three main types of hormones? Peptide/Protein (3 or more amino acids) Steroid (derived from cholesterol) Amine (derived from single amino acids) Peptide/Protein Hormones e.g. glucagon Most hormones Made in advance Synthesized like secreted proteins Stored in vesicles a Steroid Hormone: Release by exocytosis upon a signal Compare tohormone will last about -A Steroid Water soluble (dissolved in plasma) an hour or more minutes in the plasma. ***** Short half life in plasma -Lasts only will be cleared quickly We need to understand that this medication Bind to membrane receptors (next lecture) -Cause intracellular signalling (like steroid hormones) Peptide/Protein Hormones: synthesis, packaging and release How do we know what kind of hormone a cell makes via microscopy? ROUGH ER: Produces peptide hormone SMOOTH ER: Produces steroid hormone PATHWAY: mRNA translates the hormone right inside the ER --> A Preprohormone is produced --> The signal sequences that translocated the protein to the ER is cleaved --> This leaves a Prohormone --> The Prohormone is transported in a vesicle to the Golgi --> In the Golgi, the Prohormone is processed into an active Hormone and is transported into the blood stream -Importane of the Peptide By-Products: -Insulin produces C Peptide as a by product --> When insulin is released, 50% of it is absorbed in the l iver, but C Peptide isn't -If you want to get an idea of how much endogenous insulin someone is producing (while you are s upplementing them with Exogenous Insulin), we can measure how much C Peptide is (in order to m ake an estimate of how much Endogenous Insulin is being produced) Single preprohormone can contain: Several copies of the same hormone More than one type of hormone -Multiple peptides produced by the same p reprohormone -Don't focus on what these do -The IMPORTANT POINT: -The same pre-prohormone will be responsible for producing multiple h ormones or peptides "Two peptides I want you to know from this: POMC, ACTH and MSH" - Look at the next slide to understand **QUESTION ABOUT POM C AND THIS PATHWAY WILL BE ON THE EXAM Addison's Disease: Adrenal Gland stops working and stops producing Glucocorticoids -The negative feedback is gone! -CRH and ACTH will continue to increase because the Adrenal Cortex will not be able to turn off t he loop -We are stimulating ACTH, but we cant **JUST** stimulate ATCH! -We are actually stimulating the Pre-Progene POMC -A by-product is an increase in all of these others : MSH, ACTH -An Increase in MSH: stimulates melanin and will darken the skin -UNDERSTAND: atrophy of this gland (reducing glucocorticoids) will increase ACTH, CRH AND e verything that POMC encodes for --> MSH leads to darkening of the skin -If we understand the pre-prohormone, we can understand the downstream effects when its regulation is lost Peptide/Protein Hormone (Processing) Glycosylation Formation of disulf...
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This note was uploaded on 06/29/2013 for the course PSL 300 taught by Professor Ju/kee/french during the Summer '12 term at University of Toronto- Toronto.

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