1. Online Counseling Resource YCMOU ELearning Drive… School of Architecture, Science and Technology Yashwantrao Chavan Maharashtra Open University, Nashik – 422222, India

2. OC-SBT/ SBI/ SGS031-U02-02 Introduction Programmes and Courses  SEP – SBT031 – Unit 02  SEP – SBI031 – Unit 02  SEP – SGS031 – Unit 02

3. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.3 Credits  Academic Inputs by Mrs.Rasika Bhore  M.sc ( Microbiology) rasika.bhore@gmail.com

4. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.4 How to Use This Resource  Counselor at each study center should use this presentation to deliver lecture of 40-60 minutes during Face-To-Face counseling.  Discussion about students difficulties or tutorial with assignments should follow the lecture for about 40-60 minutes.  Handouts (with 6 slides on each A4 size page) of this presentation should be provided to each student.  Each student should discuss on the discussion forum all the terms which could not be understood. This will improve his writing skills and enhance knowledge level about topics, which shall be immensely useful for end exam.  Appear several times, for all the Self-Tests, available for this course.  Student can use handouts for last minutes preparation just before end exam.

5. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.5 Learning Objectives  After studying this module, you should be able to: Discuss role of prostaglandins in various body functions. Define micelle or bilayer of lipid. Describe the structure of bilayer. Explain fluid mosaic model.

6. School of Science and Technology, Online Counseling Resource… Introduction  Prostaglandins were first discovered and isolated from human semen in the 1930s by Ulf von Euler of Sweden.  Thinking they had come from the prostate gland, he named them prostaglandins.  They exist and are synthesized in virtually every cell of the body.  Prostaglandins, are like hormones in that they act as chemical messengers.  The formation of lipid bilayer or micelle is an energetically preferred process when the lipids are in an aqueous environment.  Fluid Mosaic Model describe the movement of Proteins and phospholipid molecules in bilayer. © 2007, YCMOU. All Rights Reserved.6

7. School of Science and Technology, Online Counseling Resource… About Prostaglandins  Prostaglandins are a subset of a larger family of substances called eicosanoids.  Other subgroups include thromboxanes, leukotrienes and lipoxins.  Eicosanoids are localized tissue hormones that seem to be the fundamental regulating molecules in most forms of life.  Prostaglandins are produced in the cells by the action of enzymes on essential fatty-acids.  Prostaglandins are highly potent substances that are not stored but are produced as needed by cell membranes in virtually every body tissue.  Prostaglandins vary somewhat from one another based upon subtle differences in their chemical structures. © 2007, YCMOU. All Rights Reserved.7

8. School of Science and Technology, Online Counseling Resource… Structure of Prostaglandins  Prostaglandins are unsaturated carboxylic acids, consisting of a 20 carbon skeleton that also contains a five member ring.  They are biochemically synthesized from the fatty acid, archidonic acid. © 2007, YCMOU. All Rights Reserved.8

9. School of Science and Technology, Online Counseling Resource… Series of Prostaglandins  Prostaglandins are divided into ‘Series’ type prostaglandins.  Most commonly known to women with endometriosis (tissue lining the uterus found elsewhere in body) are the prostaglandin Series 1.  Series 2 for their opposing effects or cause on pain messengers and inflammation.  In simple terms, Series 1 prostaglandins have the opposite effect of the Series 2 prostaglandins.  More recent research has focused on the balance between Series 2 and Series 3 prostaglandins. © 2007, YCMOU. All Rights Reserved.9

10. School of Science and Technology, Online Counseling Resource… Series-1 Prostaglandins  Series 1 prostaglandins reduce inflammation, dilate blood vessels, and inhibit blood clotting.  The strong anti-inflammatory properties help the body recover from injury by reducing pain, swelling and redness.  Example is- Gamma linolenic acid (GLA) © 2007, YCMOU. All Rights Reserved.10

11. School of Science and Technology, Online Counseling Resource… Series-2 & 3 Prostaglandins  The Series 2 prostaglandins play a role in swelling and inflammation at sites of damage or injury.  Also play a role in inducing birth, in regulating temperature, lowering blood pressure, and in the regulation of platelet forming and clotting.  Play a vital role for the body for without it, death can occur from the slightest cut.  However, in excess, these prostaglandins are harmful and many diseases are directly linked to excessive inflammation and blood clotting. e.g. Archidonic acid (AA).  The Series 2 group is involved in intense actions, often in response to some emergency such as injury or stress. The Series 3 group has a modulating effect.  The Series 3 prostaglandins are formed at a slower rate and work to deal with excessive Series 2 prostaglandin production.  Example is – Ecosapentaenoic acid (EPA). © 2007, YCMOU. All Rights Reserved.11

12. School of Science and Technology, Online Counseling Resource… Functions of Prostaglandins  Prostaglandin acts as receptors on various cell types.  These varied receptors have a wide variety of actions: cause constriction or dilatation in vascular smooth muscle cells. cause aggregation or disaggregation of platelets. sensitize spinal neurons to pain. constrict smooth muscle. regulate inflammatory mediation regulate calcium movement. regulate hormone regulation. control cell growth.  Prostaglandins are potent but have a short half-life. © 2007, YCMOU. All Rights Reserved.12

13. School of Science and Technology, Online Counseling Resource… Amphipathic Nature of Lipid  Some chemical compound like lipids possessing both hydrophilic and hydrophobic properties.  Such a compound is called amphiphilic or amphipathic.  As a result of having both hydrophobic and hydrophilic structural regions, some amphiphilic compounds may dissolve in water and to some extent in non-polar organic solvents.  When placed in an immiscible biphasic system consisting of aqueous and hydrophobic solvent the amphiphilic compound will partition the two phases.  The balance between hydrophobic and hydrophilic natures defines the extent of partitioning. © 2007, YCMOU. All Rights Reserved.13

14. School of Science and Technology, Online Counseling Resource… Micelle & Lipid Bilayer  Due to lipids amphiphilic nature and the fact that water is the biological solvent, lipids tend to spontaneously self assemble into supramolecular aggregates.  Self-assembly requires the participation of many lipid molecules.  It is a collective effort for the hydrophilic heads to position themselves in such a way that they are hydrated by the water and the hydrophobic ends tucked away from the water.  Two examples of such aggregates are the micelle, and the famous lipid bilayer that comprises the bulk of all cellular membranes. © 2007, YCMOU. All Rights Reserved.14

15. School of Science and Technology, Online Counseling Resource… Structure of Bilayer  A bilayer membrane is formed spontaneously when phospholipids are dispersed in an aqueous solution.  In bilayer structure, phospholipids are arranged in two leaflets with the hydrophobic tails facing each other, and the hydrophilic ends exposed to the aqueous medium.  Differences in the head group, the chain length, and the degree of saturation of fatty acids in the hydrophobic end are important factors in determining the shape of the bilayer.  Individual phospholipid molecules are able to move freely in the lateral plane of the bilayer but not in the transverse plane (flip-flop).  Small uncharged molecules are able to diffuse through the bilayer structure, but the permeability of larger or charged molecules is restricted.  Arrangement of phospholipid molecules into a bilayer in an aqueous medium follows the laws of thermodynamics and represents the structural basis for the formation of all biological membranes. © 2007, YCMOU. All Rights Reserved.15

16. School of Science and Technology, Online Counseling Resource… Fluid Mosaic Model  This membrane is partially permeable, capable of elastic movement, and has fluid properties,  Proteins and phospholipid molecules are able to move laterally in it.  Such movement can be described by the Fluid Mosaic Model.  Describes the membrane as a mosaic of lipid molecules act as a solvent for all the substances and proteins within it.  Thus proteins and lipid molecules free to diffuse laterally through the lipid matrix and migrate over the membrane.. © 2007, YCMOU. All Rights Reserved.16

17. School of Science and Technology, Online Counseling Resource… What We Learn…….  Prostaglandins are produced in the cells by the action of enzymes on essential fatty-acids.  They are unsaturated carboxylic acids, consisting of a 20 carbon skeleton with five membered ring.  Series 1 prostaglandins reduce inflammation, dilate blood vessels, and inhibit blood clotting.  The Series 2 prostaglandins play a role in swelling and inflammation at sites of damage or injury.  The Series 3 prostaglandins are formed at a slower rate and work to deal with excessive Series 2 prostaglandin production.  In bilayer structure, phospholipids are arranged in two leaflets with the hydrophobic tails facing each other, and the hydrophilic ends exposed to the aqueous medium. © 2007, YCMOU. All Rights Reserved.17

18. School of Science and Technology, Online Counseling Resource… Critical Thinking Questions  What gives stability to lipid bilayer?  If body of a person having problem in synthesizing prostaglandins, then what happens after a small injury? Why? © 2007, YCMOU. All Rights Reserved.18

19. School of Science and Technology, Online Counseling Resource… Hints for critical thinking questions  Hydrophobic tails facing each other, and the hydrophilic ends exposed to the aqueous medium.  Prostaglandins plays a role in blood clotting. © 2007, YCMOU. All Rights Reserved.19

20. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.20 Study Tips  Book Title: Essential Biochemistry Author: Pratt & Cornely  Book Title: Biochemistry Author: Campbell & Shawn

21. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.21 Study Tips www.en.wikipedia.org Prostaglandins. Lipid bile www.endo-resolved.com Endometriosis & prostaglandins. www.elmhurst.edu Prostaglandins

22. End of the Presentation Thank You