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/ SGS034-CP1-02 Introduction Programmes and Courses  SEP – SBT034 – Unit 01  SEP – SBI034 – Unit 01  SEP – SGS034 – Unit 01

3. School of Science and Technology, Online Counseling Resource… Credits  Academic Inputs by Arun Punaji More. M.Sc. (Microbiology) Experience: 11 Years arunmesh@hotmail.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: Define precursors of metabolic pathways. Describe various precursors. Describe roles of various precursors in different metabolic pathways.

6. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.6 Introduction - 1  Precursors are compounds or macromolecules which get transformed into another macromolecules which has got some function or functions.  Precursor can also be defined as the starting materials for anabolic pathways which are abundantly made available by catabolic pathways.

7. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.7 Introduction - 2  By knowing the key precursors in a metabolic pathway, one can decide the stategy to regulate that pathway; this is usefull approach to increase production of of usefull secondary metabolites having therapeutic or pharmacopic values.  By knowing key precursors in metabolic pathways one can also find some cure to correct the pathological condition arising out of defective metabolic pathway by targeting the key precursor.

8. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.8 Precursors of Gluconeogenesis  The following carbon macromolecules serve as precursors in gluconeogenesis: Pyruvate. Acetyl CoA. Lactate Alanine Glycerol

9. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.9 Precursors of Gluconeogenesis  Pyruvate:- In gluconeogenesis from two molecules are converted into one molecule of glucose. In anaerobic microorganisms pyruvate serve as precursor of ethanol for energy production. Pyruvate acts as precursor in alanine, valine and leucine biosynthesis.

10. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.10 Acetyl CoA  Acetyl CoA:- Acetyl CoA generated by carbohydrates and fatty acids oxidations is precursors for the synthesis of cholesterol. Acetyl CoA is precursor for ketone bodies which is substitute for glucose as energy source for brain cells. Acetyl CoA also acts as precursor in fatty acid synthesis.

11. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.11 Cholesterol-1  For the biosynthesis of heme, glycine, succinyl CoA and iron are precursor molecules.  Cholesterol acts as precursors to 1. sex hormones 2. bile salts. 3. vitamin D.

12. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.12 Cholesterol-2  Cholesterol is major constituent of plasma membrane.  Cholesterol is precursor of all steroid hormones such as androgens, gestagens, glucocorticosteroid, estrogens, calciferol (Vitamin D3) and mineralocorticoids.

13. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.13 Cholesterol-3  Cholesterol is precursor of testosterone and cholic acid.

14. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.14 Vitamin A  Isoprene,a five carbon compound is precursor of vitamin A.  Vitamin A is synthesize by combining four molecules of isoprene molecules.

15. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.15 Amino Acids as Precursors - 1  Many amino acids acts as precursors for synthesis of secondary metabolites.  Tyrosine is precursor of catecholamines such as dopamine and norepinephrine.  Tyrosine and tryptophan are precursors of neurotransmiter proteins.  Tyrosine is also precursor of thyroid hormones thyroxine triiodothyronine.

16. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.16 Amino Acids as Precursors - 2  Amino acids act as precursors in biosynthesis of all proteins in human body.  Alanine acts as precursor in gluconeogenesis.  Tyrosine and tryptophan are precursor of neurotransmitter.  Tyrosine is precursor of catecholamines such as dopamine and norepinephrine.

17. School of Science and Technology, Online Counseling Resource… What We Learn…..  Precursors are compounds or macromolecules.  Precursor can also be defined as the starting materials for anabolic pathways.  Following carbon macromolecules serve as precursors in gluconeogenesis: Pyruvate. Acetyl CoA. Lactate Alanine Glycerol  Cholesterol acts as precursors to 1. sex hormones 2. bile salts. 3. vitamin D

18. School of Science and Technology, Online Counseling Resource… Critical Thinking Question  What is the approach of finding out a metabolic pathway?

19. School of Science and Technology, Online Counseling Resource… Tips for Critical Thinking Question  Isolation of precursor.  Finding out regulation or controlling of metabolic processes by the intermediates of such pathway.

20. School of Science and Technology, Online Counseling Resource… Study Tips  Book Title: Fundamentals of Biochemistry Title: Fundamentals of Biochemistry Author:Dr. J. L Jain Author: Dr. J. L Jain Publication: Publication: W S. Chand and Co., New Delhi. Book Title: Principles of Biochemistry Author:Dr. H Robert Horton Author: Dr. H Robert Horton Publication: Publication: W S. Chand and Co., New Delhi.

21. End of the Presentation Thank You !