Enzyme

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???????Enzyme

• ??. ??????? ??????????????

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???????

• ??????? ??????????????????????????????
  (Biological catalyst)
• ???????????????????????? ?????????????? (Ribozyme
  or Catalytic RNA)
• gt ??????? ???????????????????????? ????
  ??????????? ???????????? ???

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?????????? (Cofactor)

• ??????????? ????????????????
  ??????????????????????????????
• ???????????????????????????? ???????? ?????????
• Holoenzyme ?????????????????????????????????????
  ??????????????
• Apoenzyme Prosthetic group

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????????????????????????????

• ?????????????????????
• ???????????????????????????????????????????
• ??????????????????????????????????????????
• ???????????????????????????????????????????????
• ?????????????????????????????????????

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Oxidoreductases

• ????????????? Oxidation-reduction
• Dehydrogenases
• Oxidases
• Reductases
• Peroxidases
• ????????????????????? NADH, NADPH, FADH2

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Transferases

• ??????????????????????????????????????????????????
  ?????
• Kinases - ????????? Phosphate
• Aminotransferases - ????????? Amino
• Transcarboxylases - ????????? Carboxyl

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Hydrolases

• ????????????? Hydrolysis
• Esterases
• Proteases
• Phosphatases
• Amylases
• Peptidases
• Ureases

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Lyases

• ??????????????????????????? C-C, C-S, C-N
• Decarboxylases
• Aldolases
• Dehydratases
• Lyases

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Isomerases

• ????????????????????????????????????????
• Epimerases
• Isomerases
• Racemases
• Mutases

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Ligases

• ????????????????????????????? ???????? C-C, C-O,
  C-S, C-N
• Synthases, Synthetases
• Thiokinases
• Carboxylases

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??????????????????????????????
??????????????????????????????????????????
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??????????????????????????????????????
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???????????????????????

• ?????????????????????????????? ???????????????????
  ??????? ???? ?????????????????????????????????????
  ????????????????????
• ????????????????????????????????????????????????

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????????????????????? ??????????????????????
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???????????? Binding Energy

• ????????????????????????????????????????????????
• ????? Functional group ???????????????????????????
  ??????
• ??????????????????????????????????????
• ????????????????? Conformation ?????????????

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?????????????????????????????
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??????????????????? (Enzyme Kinetics)

• ????????????????????????????????????????????????
  ????????????
• ???????????????????????
• ???? V0 ??? S
• ????? Enzyme ?????

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Michaelis-Menten Model

• ?????????????????????????
• 1. ???????????????????????????????????????
• 2. ?????????? gtgt ???????
• 3. ????????????????????????????? ( V0 k2 ES )
  
• 4. ES ?????????????????????? (k2 rate
  limiting step)
• Steady state kinetics

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Michaelis-Menten Equation
??? V0 Vmax / 2
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Lineweaver-Burk Equation
???????????????????? Y aX C ????? Y 1/V0
??? X 1/S
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??????????????? Kcat ??? Vmax

• Kcat Turnover number
• ??????????????????????????????????
  (Substrate) ?????????????????? ???????????????????
  ????????????? (Product) ?????????????????
  (?????????????)
• ??? Kcat ??? ?????????????????????????????????
  ?????????????????????????? (Rate limiting step)
• Vmax Kcat Et

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??????????????? Kcat / Km (Specific constant)

• ??????????????????????????????????????????????????
  ???????????? (??????????????????????????????)

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Kinetics Parameters of Chymotrypsin
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????????????????????????????????????????
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???????????????????????????? (Enzyme Inhibition)
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?????? ES complex
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???????????????????????????????? ESI complex
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??????????????????????????? (Irreversible)
Diisopropylfluorophosphate ???????????????????????
?? Chymotrypsin ?????????????????
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????????????? (Regulatory enzymes)
??????????????????????????
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Allosteric Enzyme

• ?????????????????????(Allosteric modulators)
• ????????????? (Inhibitory modulator)
• ????????????? (Stimulatory Modulator)
• ????????????????????????????????????
• ??????????????????????????????
• ?????????????????????????????? ???????????????????
  ?????????????

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??????????????????????????? ???????????????????
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???????????????????????????????????????????????
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???????????? pH
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Side Chain ??????????????? Active Site
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Side Chain ??????????????? Active Site
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?????????????