L7 Flashcards

1
Q

Why does the oxidation reaction of sucrose not proceed despite being extremely thermodynamic favorable

A

Sucrose is unreactive without a catalyst.

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2
Q

What are the 4 properties of acataly

A
  1. Does not change the equilibrium of a chemical rxn, but ACCELERATES the RATE at which EQUILIBRIUM is achieved.
  2. Functions by lowering the activation nrg of a chemical rxn.
    - Lower temp, lower pressure, lower conc, neutral pH etc…
  3. Is not used up in the rxn.
  4. Even when a catalysts forms an intermediate compounds during the reactants the catalyst is regenerated.
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3
Q

Write eqn of generic catalyst

A

A + B + C -> ABC -> AB + C

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4
Q

How do enzymes differ from chemical catalysts?

A
  • Have all the same properties as chemical catalysts.
  • With added specificity
    a) complementarity in: stereochemistry, electrostatics, H-bonds, and shape
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5
Q

Enzymes are remarkable catalysts, enhancing reaction rates by up to ____ fold!

A

10^17

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6
Q

What is “a”

A

The ratio of the value of kcat for the enzymatic rxn and the value of k^uncat of the corresponding uncatalyzed reaction in aqueous sln under the same conditions.

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7
Q

How to determine if co-factor or co-enzyme or prosthetic group?

A

N/A

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8
Q

Examples of prosthetic group?

A
  1. FMN
  2. FAD
  3. Heme
  4. MoCo
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9
Q

Example of coenzymes?

A

Organics, bound loosely e.g.

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10
Q

Example of cofactors?

A

Fe / Zn ions

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11
Q

Example of cosubstrate?

A

NAD+

ATP

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12
Q

Example of inorganic factors?

A

Zn2+

Fe-S cluster

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13
Q

Define Apoenzyme

A

enzyme with cofactor

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14
Q

What is the enzyme commission #

A

N/A

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15
Q

Example:

EC 3.4.21.89

A
3 = hydrolase
4 = acting on a peptide bond
21 = uses a serine nucleophile
89 = specific protease
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16
Q

What are the 6 classes of enzymes in order of their classes

A
  1. Oxidoreductases aka dehydrogenase
  2. Transferases
  3. Hydrolases
  4. Hydratase
  5. Isomerase
  6. Ligase
17
Q
  1. Draw a dehydroganese/oxidoreductase rxn.
  2. What does it transfer?
  3. What does it usually use as cofactors?
A
  1. ethanol + NAD+

- –>NAD:alcohol / dehydrogenase

18
Q
  1. Draw a transferase rxn.

2. What does it transfer?

A
  1. Glucose + ATP

- ———> ATP:glucose/ phosphotransferrase

19
Q
  1. Draw a hydrolases rxn.

2. Example?

A
  1. glucose-6-phosphate + H2O

- ———–> glucose-6- phosphatase

20
Q
  1. Draw a hydrotases rxn.

2. Another name for hydratases?

A
  1. cis-aconitate + H2O

- ————-> aconitate hydratase

21
Q
  1. Draw a isomerase rxn.
A

Glc-6P

————–> glc-6-phosphatase isomerase

22
Q
  1. Draw a ligase rxn.
A

Pyruvate + Bicarbonate + ATP

———> pyruvate carboxylase