Enzymes Flashcards

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1
Q

How do enzymes reduce activation energy

A

Correctly orients substrates
Strains substrate bonds
Proved a favorable micro environment (R groups)
Brief covalent bonds with substrate

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2
Q

What is an enzyme

A

Helps to lower Ea allowing reactions to proceed more efficiently

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3
Q

What is activation energy

A

Initial amount of energy needed for the reaction to proceed

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4
Q

What is the allosteric site

A

Site located away from the active duty where the non competitive inhibitor can fit

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5
Q

Where is the energy of ATP stored

A

In bonds between its terminal phosphate groups

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6
Q

Where are enzymes located

A

It can either be free in the cytoskeleton or be bound to membranes and organelles

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7
Q

What does free energy look like as the reaction progresses on a graph

A

Reactions without and enzyme have a higher Vmax than reactions with an enzyme, but they both meet at y=0

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8
Q

What does the graph of concentration substrate look like with and without inhibitors

A

Without an inhibitor the rate has a higher Km than with an inhibitor but they both have the same 1/2 Vmax and Vmax

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9
Q

What is the product of a reaction used for in feedback inhibition

A

The product directly inhibits the enzyme that made it

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10
Q

What happens when the acidity increases (H+)

A

The H+ is attracted to O, OH becomes an ion dipole (weak) and the molecule becomes more basic

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11
Q

What happens to enzymes when the temperature is decreased

A

The bonds are unable to move and are inflexible

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12
Q

What happens to enzymes when you increase the temperature

A

The energy increases causing the molecules to fall apart

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13
Q

During the catalytic cycle what happens to thermodynamics

A

The thermodynamics are unchanged throughout the catalytic cycle

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14
Q

How does feedback inhibition regulate enzymatic activity in the biochemical pathway

A

It can shut down the pathway if something goes wrong

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15
Q

What is feedback inhibition

A

A way to regulate enzymatic activity in the biochemical pathway

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16
Q

What is an example of a biochemical pathway

A

Glycolysis

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17
Q

What is a biochemical pathway

A

The product of a reaction becomes the substrate for the next reaction

18
Q

What is the 1/2 Vmax

A

Half of the Vmax value

19
Q

What is Km

A

The concentration substrate it takes to reach 1/2 Vmax

20
Q

Is the reaction rate higher or lower without the inhibitor? With the inhibitor?

A

Without: the reaction rate is higher
With: the reaction rate is lower

21
Q

How would you get rid of the competitive inhibitor

A

Add more substrate

22
Q

What is the Vmax

A

The maximum reaction rate that can happen within that system

23
Q

Does Ea have an effect on delta g

A

No matter what Ea is, delta G doesn’t change

24
Q

What happens when substrate concentration increases

A

Reaction rate increases and eventually levels off

25
Q

What is a michaelis menten plot

A

Shows substrate concentration vs reaction rates

26
Q

What is a non competitive inhibitor

A

Bonds to the allosteric site which changed the shape of the active site

27
Q

What is a competitive inhibitor

A

Mimics substrate and competes with the substrate for access to active site

28
Q

What are inhibitors

A

Controls enzyme activity

29
Q

What is normal binding

A

A substrate can normally bind to the active site of an enzyme

30
Q

Why is Mg2+ essential for ATP hydrolysis

A

It brings substrates together which stabilized molecules

31
Q

What are organic cofactors

A

Small, non-protein organic molecules (vitamins)

32
Q

What are inorganic cofactors

A

Metallic ions that can move electrons from covalent bonds (Mg, zinc, copper, etc.)

33
Q

Enzymes are…

A

Substrate specific, meaning they only react with specific substances

34
Q

What is the 1st step of the catalytic cycle

A

Substrates enter the active site

35
Q

What is the second step of the catalytic cycle

A

Substrates are held in the active site by weak interactions

36
Q

What is the third step of the catalytic cycle

A

The active site lowers the Ea

37
Q

What is the 4th step of the catalytic cycle

A

Substrates are converted into products

38
Q

What is the 5th step of the catalytic cycle

A

The products are released

39
Q

What stage of protein structure is the active site in

A

Quaternary structure

40
Q

What does an increase of G cause during the catalytic cycle

A

Unstable transition state
Bonds break and new ones form
Free energy is released (spontaneous)