Ch. 6 Enzymes Part 1 (Exam 2) Flashcards

Kinetics, Catalysis, Enzymes, Rate of Reaction, Mechanism of Enzyme Catalysis

1
Q

What is the relationship between high activation energy, reaction rate, and the number of collisions in a reaction?

A

High activation energy = lower reaction rate = lower # of collisions

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2
Q

In an uncatalyzed Boltzmann distribution vs. time, how does temp affect the number of particles/molecules at any given activation energy?

A

Lower temp = fewer reacting particles/molecules

Higher temp = more reacting particles/molecules

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3
Q

Under what condition can the particles/molecules in a Boltzmann distribution react?

A

The particles/molecules must have energy that surpasses the activation energy

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4
Q

How do catalysts affect reaction rate?

A

They increase reaction rate by lowering activation energy

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5
Q

What 2 things do catalysts not change?

A

1) Equilibrium position

2) Change in Gibbs energy

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6
Q

Define activation energy.

A

Energy needed for reactants to reach the transition state

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7
Q

Define transition state.

A

Midpoint between reactants and products

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8
Q

What happens to chemical bonds during the transition state?

A

Old bonds are breaking and new bonds are forming

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9
Q

What is another name for transition state?

A

Intermediate state

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10
Q

Why is the transition state the least stable phase on a reaction curve?

A

It is high energy

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11
Q

How does a catalyst affect the Boltzmann distribution of activation energy in terms of the amount of freely reacting particles?

A

Catalyzed activation energy has more reacting particles than uncatalyzed activation energy

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12
Q

What are enzymes?

A

Biological catalysts

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13
Q

In what form/shape will you mostly find enzymes?

A

Globular proteins

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14
Q

How do amino acids help active sites?

A

They lower the transition state energy

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15
Q

Give an example of how product-specific enzymes are.

A

They typically produce only one stereoisomer

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16
Q

What does a chemical reaction not change?

A

The enzyme

17
Q

What are two important things about active sites?

A

1) Enzyme surface is binding location for substrate

2) Substrates are placed in precise orientation

18
Q

What is another term for reactant?

A

Substrate

19
Q

In what 2 ways do substrates bind to active sites?

A

Non-covalently and reversibly

20
Q

What changes when a substrate binds to an enzyme,, and what is this called?

A

The 3D shape known as the enzyme-substrate complex (ES)

21
Q

What is the induced fit model?

A

The complimentary fit of the transition state

22
Q

How does the induced fit model aid in transition state formation?

A

The substrate fits into the enzyme forming the ES, which aids in transition state formation

23
Q

What are 2 important factors in a substrate binding to an enzyme?

A

1) Proximity

2) Orientation

24
Q

What is the proximity effect?

A

It places substrates closer together so that the # of collisions increases to, in sum, increase the reaction rate

25
Q

What is the orientation effect?

A

It places substrate into the maximally reactive conformation/shape