Brainscape's Knowledge GenomeTM

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


See full index

BIOC192 > Enzymes > Flashcards

Enzymes Flashcards

1
Q

Enzymes role

A

Increase rate of chemical reactions
Doesn’t change free energy of products or reactants
Decrease activation energy

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

Basis of catalysis

A

Reactions through high-energy transition states

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

Oxidoreductases

A

Redox

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

Transferases

A

Transfer of functional groups

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

Hydrolases

A

Hydrolysis reactions

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

Lyases

A

Non-hydrolytic breaking/making bonds

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

Isomerases

A

Transfer within molecule yield isomeric form

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

Ligases

A

Join 2 molecules

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

Active site

A

Bind substrate via a.a side chains via weak interactions

Determines specificity of reaction

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

Types of bonds

A

Ionic
Hydrogen
Van der Waals interactions
Covalent

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

Models for enzyme fits

A

Lock and key
Induced fit
Complementary to substrate

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

Enzymes fit bonds

A

Many weak interactions

Specificity and reversibility

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

Types of catalysis

A 
Acid-base
Covalent
Redox & radical
Geometric effects
Stabilisation through transition state 
Co factors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Types of co-factors

A 
Metal ions - orientates substrates
Co enzymes (from vitamins)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Evolutionary history

A

Same structure, unique specificties

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

Convergent evolution

A

Same catalytic triad - different order & structure

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

Chymotrypsin

A

Acid - base and covalent cataysis

Cleaves protein at hydrophobic residue = easy to be absorbed in digestion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Oxyanion hole lowers..

A

activation energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Model for Michaelis-Menten equation

A

E+S <=> ES -> E+P

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

K1 & K-1 =

A

How tightly substrate binds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

K2 =

A

Rate of cataylsis, energy of activation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

[ES] =

A

Controls rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Progress curve

A

Appearance of products over time
Vo
Tangant to beginning of reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Vo proportional [E] when

A

substrate excess

25
Q

Vmax =

A

max velocity when [S] infinite

26
Q

Km =

A

Vmax/2

27
Q

Michaelis-Menten equation

A

Vobs = Vmax[S]/

Km + [S]

28
Q

Michaelis-Menten assumptions

A

Product not convented to substrate
Rate of [ES] formation and breakdown equal
Inital rate = [S] doesn’t change significantly

29
Q

First order kinetics

A

ES -> E + P

30
Q

Lineweaver-Burk Plot x and y axis

A 
x = 1/[S]
y = 1/Vo
31
Q

Lineweaver-Burk Plot x and y intercept

A 
x = -1/Km
y = 1/Vmax
32
Q

Km high/low =

A

low/high affinity (opposite)

33
Q

Kcat

A

No of substrate converted to product, per enzyme, per unit of time
Catalytic activity

34
Q

Catalytic efficiency

A

kcat/km = higher the better

Limit - diffusion controlled rate (10^8s-1m-1)

35
Q

Inhibitors function

A

bind to enzyme and reduce activity

36
Q

Irreversible inhibitor

A

Binds covalently

Permantly inactivates

37
Q

Reversible inhibitor

A

Bind noncovantly
Can be released
Competitive and noncompetitive

38
Q

Competitive reversible inhibitor

A 
Compete with substrate in active site
Vmax same
Km increase
[S] increase = outcompete inhibitor
Slower rate
39
Q

Noncompetitive reversible inhibitor

A

Binds to different site to active site
Pure
Mixed

40
Q

Pure noncompetitive reversible inhibitor

A

Vmax decrease

Km same

41
Q

Mixed noncompetitive reversible inhibitor

A

Vmax decrease

Km increase

42
Q

Enzymes and treatment eg 2 types of alcohol

A

Toxins produced during metabolism of some alcohols

Alcohol with lower km = likely to be metabolised e ethanol

43
Q

Receptors types

A

Across membrane
Transmit signal across membrane
Membrance bound enzymes
Intracellular

44
Q

Enzyme features

A

1 active site
BInds and changes substrates into products
Membrane bound/free in cytosol

45
Q

Receptor features

A

Several binding site
Bind and release ligans unchanges
Membrane bound/free in cytosol

46
Q

Receptor definition

A

Protein molecules that receives chemical signals outside cells

47
Q

Ligand definition

A

Molecule/drug that binds to receptor

48
Q

Agonist

A

Chemical capable of activating receptor to indue response

49
Q

Antagonist

A

Blocks receptor and stops effects

50
Q

Alcohol _____ at _____ receptor

A

agonist at GABAa

51
Q

GABAa receptor

A

Membrane bound ligand gated Cl- channel

Iinhibitory

52
Q

GABAa receptor + alcohol

A

Open channel, allows Cl- into cell

Decrease activity in nervous system

53
Q

Consequences of alcohol

A

Varies on dose and person

Person = different expression of receptor = different response

54
Q

Useful features to build drug

A

Catalyse reactions
Active site
Preferred substrates
Can be inhibited (competitive)

55
Q

Design inhibitor

A

Know active site and substrate

56
Q

HIV Protease inhibitor active site

A

Cleaves a.a. with common structure with hydrophobic rings (bulky)
+ Asp residues = position substrate

57
Q

HIV Protease inhibitor substrate

A

Cleave peptide bond from long a.a chain

58
Q

Making drug

A

1) build peptide-like backbone
2) add bulky side groups to fit active site
3) rest of drug = soluble

59
Q

Testing

A

Competitive = Vmax same, Km increase

BIOC192 (6 decks)

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