BHEEMA_2ND_ENZYME_4th_paper.pptx..............

Msc2nd sem

1. GOVERNMENT NEHRU PG COLLEGE DONGARGARH SUBMITTED BY BHEEMA MSC. BOTANY SEM. II DEPARTMENT OF BOTONY SESSION 2023-24 ENZYMOLOGY Guided by mR. avinash singh Head of department

2. The study of enzymes is called enzymology

3. SYNOPSIS INTRODUCTION DISCOVERY WHAT ARE ENZYME? NATURE OF ENZYME STRUCTURE OF ENZYME CLASSIFICATION 0F ENZYME MACHANISM OF ENZYME ISOENZYME ALOSTRATRIC MECHANISM INHIBITION OF ENZYME ACTION FACTOR AFFECTING ENZYME SIGNIFICANCE OF ENZYME CONCLUSION REFERENCE REVERSIBLE INHIBITION INREVERSIBLE INHIBITION LOCK & KEY HYPOTHESIS INDUCED MODEL FIT

4. INTRODUCTION Enzyme are biological catalysts that speed up the rate of the biological reaction. Enzyme are protein in nature . Notes- Ribozyme is enzyme but it is not in protein nature. All enzyme are specific . Enzyme are thermoliable .

5. DISCOVERY Lard Buchner (1860-1917) Lames Sumner(1887-1955) J.B.S.Haldane (1892-1964) w.Kuhne 1877

6. WHAT ARE ENZYME? Enzyme are protein that function as biological catalysts a catalyst is a substance that speed up a chemical reaction but its not change by the reaction. Enzyme catalyze all aspects of cell metabolism. STRUCTURE OF ENZYME

7. NATURE OF ENZYME Protein enzymes are classified into two types- SIMPLE ENZYME - They are formed of protein only. Ex.- Amaylase , Pepsine CONJUGATED ENZYME –They are formed of protein part and non protein part. Ex.- Hemoglobin

8. ENZYME S imple Conjugated P rotein Non- protein Cofactor Coenzyme M etals

9. CLASSIICATION OF ENZYME ENZYME FUNCTION EXAMPLE Oxidoreductases Reduction/Oxidation Lactate Tranferases Move chemical group Hexokinase Hydrolases Hydrolysis ; bond cleavage with transfer of functional group of water Lysozym e Lyases Non-hydrolytic bond cleavage Fumarase Isomerases Isomerization reaction Triose phosphate isomerase Ligases Synthesis of new covalent bond between substrates using ATP hydrolysis DNA polymerase RNA polymerase

10. MECHANISM OF ENZYME LOCK & KEY HYPOTHESIS- Emil Fisher 1890 As one specific key can open only a specific lock in the same manner the specific enzyme can transfer only one specific substrate into product. According to this model the active site has a rigid structure there is on modification or flexibility in the active site before during or after enzyme action.

11. INDUCE FIT HYPOTHESIS – Daniel Koshland in 1959 Enzyme are flexible shape that the shapes of the active sites can be markedly modified by the binding of substrate . The binding of the substrate induces a conformational change in the enzyme that result in a complementary fit once the substrate.

12. ISOENZYME Isozyme are enzymes that differ in amino acid sequence but catalyze the same chemical reaction . They are encoded by different genes located at different loci. Isozyme differ from allozyme , which are enzymes that arise from alternative froms of the same gene. Ex- lactate dehydrogenase(LDH) which catalyzes the reversible conversion of pyruvate to lactate. Isozyme Nature of subunit Location LDH1 HHHH(H4) Heart and RBCs LDH2 HHHM(H3M1) Reticuloendothelial system LDH3 HHMM(H2M2) In the lungs LDH4 HMMM(H1M3) Kidneys, placenta LDH5 MMMM(M4) In the liver and striated muscle

13. AL L OSTRATIC MACHANISM Allosteric enzyme ( Greek words allo meaning other and steric meaning place or site) are a class of regulatory enzymes which increase or decrease catalytic activity in response to certain signals . These enzymes function through reversible non- covalent binding of regulatory compound called allosteric modulator. Modulator molecules are of two types 1 ) positive modulator (Activator) , 2) Negative modulator ( inhibitors). Homotropic and Hetrotropic

14. Enzyme Substrate Inhibitor Activator Biosynthetic L-threonine deaminase L-Threonine L-Isoleucine L-Valine NAD – isocitric dehydrogenase D- Isocitrate + NAD + α - Ketoglutarate Citrate

15. INHIBITION OF ENZYME Inhibition of enzyme Reversible inhibition irreversible inhibition Competitive inhibition Un -competitive inhibition Mixed inhibition Non-competitive

16. Competitive inhibitor:- A competitive inhibitor compete s with the substrate for the active site of an enzyme. While the inhibitor (I) occupies the active site it prevents binding of the substrate to the enzymes. Many competitive inhibitor are structurally similar to the substrate and combine with the enzymes to from an EI complex

17. Non- competitive inhibition Non-competitive inhibition, a type of allosteric regulation, is a specific type of enzyme inhibition characterized by an inhibitor binding to an allosteric site resulting in decreased efficacy of the enzyme. An allosteric site is simply a site that differs from the active site- where the substrate binds.

18. Uncompetitive inhibitions An uncompetitive inhibitor binds at a site distinct from the substrate active site any unlike a competitive inhibitor, binds only to the ES complex. MIXED INHIBITOR- A mixed inhibitor also binds at a site distinct from the substrate active site, but it binds to either E or ES the rate e°.

19. IRREVERSIBLE An irreversible inhibitor bind to the active site of the enzyme by an irresistible reaction. E+I EI A covalent bond is usually formed between inhibitor and enzyme. Inhibitor dissociates very slowly from the enzyme and enzymes catalytic activity is permanently inhibiters .

20. FACTOR’S EFFECTING OF ENZYME Factor effecting INHIBITORS PH COAFACTOR AND COENZYME CONCENTRATION OF SUBSTRATE TEMPRATURE TIME Factor effect

21. Significant of enzymes Enzyme play in important role in metabolism , Diagnosis. All biochemical reactions are enzyme catalyzed in the living organism. Enzyme can be used therapeutically such as digestive enzymes .

22. Conclusion Enzyme have both biological and chemical attributes their sequences and structure delineate their role in the genome and proteome of all living organisms and their ability to catalyzed chemical reactions extends their biological function to metabolic pathways and networks

23. Reference Enzymology – Trevor palmer, Philip bonner Principle of biochemistry- Lehninger Life science- Usha mina , Pranav kumar

24. THANK YOU