Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biotechnology > Biocatalysis 2 > Flashcards

Biocatalysis 2 Flashcards

1
Q

What symbol represents the turnover number?

A

K2 (Kcat) - rate of catalytic conversion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is kcat X Eo equivalent to?

A

Vmax

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is Km a measure of?

A

The binding affinity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the unit of activity?

A

1U = mmol product/min/mg E (per active site)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the calculation for proficiency?

A

Kcat/Kuncat (rate of uncatalysed reaction)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is specificity a measure of?

A

Compares activity on two substrates

(kcat/Km)1 / (kcat/Km)2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the benchmark of the enantiomeric ratio?

A

~100

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the Y intercept on a line-weaver burk plot?

A

The y intercept is 1/Vmax

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the X intercept on a line-weaver burk plot?

A

The X intercept is -1/Km

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the gradient of the line-weaver burk plot?

A

The gradient = Km/Vmax

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Why is there a large error rate in line-weaver burk plot?

A

There is a large error rate because of the reciprocal values – small changes in substrate concentrations, produced large error.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the benefit of the Eadie-hofstee plot over the line-weaver burk plot?

A

The Y axis is not a reciprocal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the benefit of the Hanes woolf plot over the Eadie-hofstee plot?

A

No longer has the substrate as the denominator hence the substrate error dependence is almost completely removed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is competitive inhibition?

A

Inhibitor competes for the active site.

Reaction rate is the same but interfers with binding kinetics hence Km changes and Vmax stays the same

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is Non-competitive inhibition?

A

The substrate binds distal from the active site – allosteric –binds E or ES
Constant Km, but the Vmax changes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What uncompetitive inhibition?

A

Binds the ES complex and prevents productive reaction

Vmax gets smaller and Km gets bigger

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the mathematical link between the temperature and the rate of the reaction?

A

Rate k = Ae-^(Ea/RT)

18
Q

What are the two predicted states in the two state model?

A

Folded or unfolded

19
Q

What is the equilibrium constant that connects these states?

A

K

K is a thermodynamic parameter, that relates to the free energy of unfolding.

20
Q

What is the melting point?

A

The temperature at which half the enzyme is unfolded

21
Q

What is the temperature when DeltaG is at maximum?

A

Ts

22
Q

In the 3 state model what are the 3 states?

A

folded, unfolded, denatured

E U D

23
Q

Which is measured experiemtnally?
a) Kdobs
b) K
C) k

A

Kdobs

K

24
Q

What is the equation for the half life of an enzyme?

A

Thalf = ln 2/ kdobs

25
Q

How is Kdobs determined?

A

Plot the remaining enzyme activity vs. time to determine the half-life
Gradient is -kd

26
Q

What is the equation for remaining enzyme activity?

A

lnE/E0

27
Q

What is Enzyme Immobilisation?

A

Immobilising enzymes on a support to reduce unfolding by restricting movement

28
Q

What is coupling?

A

Enzyme can be attached to a solid carrier or cross link the enzyme to itself/carrier
Enzyme is in solid state and substrate must move from aqueous state to solid

29
Q

What is entrapment?

A

Hiding Enzyme behind something/ in a pore

30
Q

What is volumetric productivity?

A

In the whole volume of the reaction (not specific).

Weight of Product Formed/Volume/ Time

31
Q

What is a monophasic reaction?

A

Substrate ad enzyme are in a single phase

solvent is miscible

32
Q

What is a biphasic reaction?

A

Enzyme is in an aqueous reaction and substrate in organic phase
This involves a mass transfer hence stir to help diffusion

33
Q

What is a dispersed enzyme?

A

Freeze dried enzyme (in solid phase)

34
Q

Why do enzyme deactivate in solvents?

A

No hydrophobic driving force to remain folded

Also less active in solvents

35
Q

What are the two theories to explain why the original solution the lyophilised enzymes are from affects the function?

A

Some salts retain more water

Fume silicia causes formation of smaller crystals - larger SA

36
Q

What is the B-factor?

A

A measure of ability to move from mean position

37
Q

What is the aim of medium engineering?

A

To produce a medium that improves enantiomeric ratio

38
Q

What laboratory tool might be used to regenerate cofactors?

A

electrodes

- REDOX reactions

39
Q

How might 1 enzyme be used to regenerate an co factor and still discourage the reverse reaction?

A

2nd substrate is introduced to regenerate the cofactor without having to perform the reverse reaction

40
Q

How might 2 enzymes be used to regenerate an co-factor?

A

Second enzyme converts a second substrate to a product to generate the co factor

41
Q

What is an issue with using 1 enzyme to regenerate the cofactor?

A

The enzyme is rate limited as it has to perform both reactions

42
Q

What is biotransformation?

A

Using cells to regenerate co-factors when multiple reaction steps and enzymes are required to do so.

Biotechnology (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions