Enzyme - Catalysis Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

Transistion State Analogues

A

These stabilise favoured transistion state geometry evolved in enzymes for catalysis.

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

What are TS Analogues?

A

High energy intermediates existing betwene the substrate and the products of the catalysis.

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

What is the first stage in enzymes catalysis?

A

Formaiton of the ES complex,

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

What does ES complex formation depnd on?

A

Diffusion, specificity within the active site, binding and catalysis

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

Activation Energy

A

This is a kinetic paramter being the energy of the transition for a given reaction relative to the intial state.

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

Where is activaiton energy important?

A

Energonic thermodynamically unfavourable reactions, requiring energy input.

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

Transistion State

A

THis is a local energy maximum along the reaction co-ordinate

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

Why are enzymes important?

A

Stabilisation of the transistion state, lowering activation enery

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

How can transistion state formation be thermodynamically described?

A

Reduction of the substrate free energy, where the transistion high energy state has molecules in an unstable conformation

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

Induced Fit Model

A

This was proposed by Koshland in 1958 to explain protein conformational changes in ES binding

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

What does the IFM describe?

A

Optimization of the interface with ES substrate formation

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

What do IFM CC result in?

A

Reorientation of AA through enzymatic changes from intermoleuclar interactions

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

Why is the transistion states dificult to reach/maintain?

A

Its instability, requiring chemical bond ormation/breaking.

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

What does AE measure?

A

Difference in energy of reactants to transistion state

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

How can transisiton state be described quantum mechanically?

A

Promotion of electrons to higher energy levels allowing formaiton of new chemical bonds

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

What isan example of a transistion state analogue?

A

Yeast aldolase

17
Q

Aldolase

A

This catalyses reversible reaction of converting F16BP into DHAP and GA3P

18
Q

What can analogues be used for?

A

Design inhibitors of it, identifying key functional groups and stereochemistry in the reaction to design a moleucle mimicing thease features.

19
Q

Sterochemistry

A

This is the chemistry of 3D arrangement of atoms in molecules

20
Q

What is an example of a TSA?

A

Phosphoglycolohydroxamate mimicing Enediolate transistion state

21
Q

How is enediolate distinct from PGD?

A

PGD contains a hydroxamate group mimicing the intermediary, binding by covalent bond to the active site.

22
Q

What are the Km of PGD transistion state analogue?

A

DHAP =4x10^-4M
PGD Ki =1x10^-8M
Km/K = 4X10^4

23
Q

How does Zinc cofactors stabilise Enediol?

A

Co-ordination to the negative charge of the oxygen.

24
Q

Adenosine Deaminase

A

THis is an enzyme of the purine metabolism which catalyse the irreversible deamination of adenosine and deoxyadenosine to ionsine and deoxyinosine

25
Q

What does Adenosine Deaminase form?

A

A transistio nstate of adenosine with an inhibitory form purine ribonucleotide with a Km of 3x10^-5M and Ki of 3x10^-15M
Km/Ki = 1x10^8

26
Q

How does Purine Ribonucleoside and Adenosine differ?

A

Purine Ribonucleoside contains a H instead of a H2N