Specificity of Enzyme (Specific Activity of Enzyme) PPT by easybiologyclass Slideshare

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  1. 1. SPECIFICITY OF ENZYMEMechanism of Enzyme - Substrate Specificity
  2. 2. 7 ,.- .I . .__ 1 r _ I . . . /{.251"There is more to life than increasing its speed. ..Mahatma Gandhiwww.easybiologyclass.comIs)
  3. 3. 7. ).m Learning objectives:I Understand enzyme specicity I Importance of enzyme specicity I Classication of enzyme specicity I Different types of enzyme specicity: - @.Bond specicity @.Group specicity @.Substrate specicity @.Optical or Stereo specicity @.Geometrical specicity,3-@.Co-factor specicitywwm easybiologyclass.com..- .I . *Lr _
  4. 4. SPECIFICITY OF ENZYMES ' .EASY BIOLOGY CIAIntroductionI Enzymes are biological catalystsI Almost all enzymes are specialized proteinsI Ribozymes are the exception (they are RNA with catalytic properties) I Important characteristic features of enzyme are: > Catalytic Power (ratio of enzyme catalyzed rate of a reaction to theun-catalyzed rate) > Regulation (control of enzymatic reaction)> Spec1city(SeIectiVity of enzyme to their substrate)
  5. 5. SPECIFICITY 0E ENZYMES What is enzyme specificity?C Ability of an enzyme to choose exact substrate F It is a molecular recognition mechanismF Recognition and specificity is based on structural complementarityConformational Complementarity of Enzyme and SubstrateSubstrateEnzyme EnzymeConformational Asymmetry ofSimilar Conformational Symmetry of Enzyme and SubstrateEnzyme and Substratewww.easybiologyclass.comon
  6. 6. SPECIFICITY OE ENZYMES Different types of enzyme specificity Enzymes shows different degree of specicity,grouped into 6 categories1. Bond specicity 2. Group specicity 3. Substrate specificity 4 Optical or Stereo specicity 5. Geometrical specicity6. Co-factor specicitywww.easybiologyclass.com
  7. 7. SPECIFICITY oE ENZYMES ( 1).Bond specicity:F Specific to substrates having similar bonds and similar structures _ _ _ _ Bond Specicityofl-Inzyme rf Spec1f1c1ty1s less Peptide Bond P fd B d C Also called relative specificityep 1 9 on I I Glycine -(ll-'~ - Glycine Alanine E. Valine. Enzyme EnzymeExample ,Peptidase enzyme are spcci t to llllllllt bond formed between any amino acidsV Amylase can hydrolyze or-1-4 glycosidic linkage in starch and glycogen F Lipase can hydrolyze ester bond between glycerol and fatty acid in any fatsW Proteinases hydrolyzes all peptide bonds formed by any amino acids www. easybiologyclass. com
  8. 8. SPECIFICITY OF ENZYMES(2).Group spec1'city:I Enzyme specific to type of bond and groups surrounding it I More specificity than bond specificityI Also called moderate specificity and structural specificityI Endopeptidases and exopeptidaces are classical examplesExample:Pepsin hydrolyze a peptide bond in which the amino group iscontributed by an aromatic amino acid (phenyl alanine,tyrosine and tryptophan)Pepsin Cleavage Sites C- TerminalN- Terminal
  9. 9. SPECIFICITY OF ENZYMES(2).Group specicity:Trypsin hydrolyze a peptide bond in which amino group is contributed by abasic amino acid (lysine,arginine and histidine)Trypsin Cleavage Sites N- Terminal 6- TerminalChymotrypsin hydrolyze a peptide bond in which the carboxyl group iscontributed by an aromatic amino acid (phenylalanine,tyrosine and tryptophan)Chymotrypsin Cleavage SitesN- Terminal Terminal
  10. 10. SPECIFICETY OF ENZYIVIES(2).Group specicity: Aminopeptidase hydrolyzes the peptide bond form N terminal of proteinAminopeptidase Cleavage Site _ N- Terminal C Te""'"I . ~.uf . (3%I'D j ': l'-I T H j (A3 ?" '1 ?K1: j Carboxypeptidase hydrolyzes the peptide bond from C terminal of proteinN- Terminal 0 Terminalwww. easybiologyclass. com 1 0
  11. 11. SPECIFICITY OF ENZYMES ' . IAN BIOLOGY QM? ( 3 ).Substrate specicity I Enzyme specific to only one substrate and one reaction I Specificity is high I Also called absolute specicity I Example:I Lactase acts only on lactose I Sucrase act only on sucroseI Maltase acts only on maltose
  12. 12. SPECIFICETY OF ENZYMES(4).Optical specicityAlso called stereo-specicityEnzyme are specific not only to substrate but also to its optical configurationSpecificity is very high Example:L-amino acid oxidase acts only on L-amino acidsStereo specificity of En/ .ymcs/ l, L 4: % K 7 , " . _/ | (/1 IL: " _ C. Cc IH " *1 .Enzyme I -M ~ Enzyme L-Alanine Oxidase & I. -Alanine Oxidase &L-Alanine D-Alaninewww.easybiologyclass.com
  13. 13. SPECIFICITY OF ENZYMES(4).Optical speci'city I Damino acid oxidase acts only on Damino acidsI oiglycosidic bonds of starch and glycogen are hydrolyzed only by (X-glycosidase (oi-amylase)I [3-glycosidic bonds of cellulose are hydrolyzed only by B-glycosidase (B-amylase)Stereo specicity of Enzymesav-1-4 Linked 3'14 Linked Glucose (starch) Glucose (Cellulose) < i i >.,< > q 0 o S 7 .a-Amylase a-Amylase
  14. 14. SPECIFICETY OF ENZYMES(5).Geometrical specificity Ft Here specificityis less rf Enzyme can act on different substrates having similar molecular geometryF7 Example:Alcohol dehydrogenase can oxidize ethanol,methanol and propanol to yields corresponding aldehydesGeometric specicity of EiizyinesMethanol Ethanol ; A sr ;9 /6 / O /6'/ o 6' '/ Oo I9 0/ Enzyme6 6 Enzyme ""'_ De-Vd9"5e Alcohol Dehydrogenase Amng " Ethaml Acting on Methanolwwmeasybiologyclass.com 14
  15. 15. SPECIFICITY OF ENZYMES ' .5EASY BIOLOGV (LAOS(6).Co-factorspecicityI Specificity is highI Here enzyme are specific to substrate and co-factorI Only correct combination of substrate & co-factor allow enzymatic reactionI In the absence of specific co-factor,the enzyme will be inactive even if thereare plenty of substrates
  16. 16. Formore iiifbnnation,please log on to:WW" VV . easybiologyclass.C O InFor Video tutorials please subscribe the You Tube clianiiel:You 1 easybiologyclassIlian&You.. . E-mail us @:._._ easybiologyclass@gmail. com 0 mail@easybiologyclass. com I _visit:www. easybiologyclass. com