Brainscape's Knowledge GenomeTM

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


See full index

BIOL1024 > Enzymes > Flashcards

Enzymes Flashcards

1
Q

Define enzyme

A

One or more polypeptide chains forming a catalytic active site

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

Define substrate

A

Molecule which binds active site and undergoes a chemical reaction

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

Define product

A

The result of the enzyme action

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

What does a anabolic reaction mean?

A

Smaller reactants form larger products

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

What does a catabolic reaction mean?

A

Larger products from smaller products

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

What are the six classes of enzymes?

A 
Oxidoreductases
Transferases
Hydrolases
Lyases
Isomerases
Ligases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What 2 things does reaction rate depend on?

A

Speed of reaction / Rate constant k

Number of reactions happening

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

What are the advantages of enzymes?

A

Reusable
Specific
Efficient
Controllable

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

How do enzymes ‘speed up’ reactions?

A

By lowering the activation energy

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

What are the 2 proposed models for enzyme reactions?

A

Lock and Key- Fischer

Induced Fit -Koshland

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

Each change in activation energy of 5kJ/mol= how many times faster?

A

10x

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

What is the enzyme attachment theory?

A

Ogston’s 3 point binding theory

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

What 2 things determines reaction specficity?

A

3D arrangement of residues

Chemical properties of the residues

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

Define Co-Enzymes

A

Organic molecules which provide/remove groups for reaction

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

What 3 things can you compare enzymes via?

A

Turnover number
Efficiency
Potency

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

What is the catalytic triad?

A

Often only 3 amino acids perform the actual catalyst

17
Q

What 3 things can an active site also contain?

A

Metal cofactors
COenzymes
Prosthetic groups

18
Q

Define isozymes

A

Different enzymes same substrate

19
Q

What does spectrophotometer measure?

A

Starting point is the measuring the change in [S] or [P] over the time after addition of enzyme

20
Q

What is an indication of purity?

A

Enzyme activity/ total amount of protein

21
Q

Describe what the role of an enzyme is ?

A

Provides an alternative route from substrate to products requiring less energy

So more molecules have that energy so more go from S to P per second and equilibrium is reached sooner

22
Q

Reactions can be pushed backwards by what?

A

Increasing the [product]

23
Q

Keq=

A

Keq= K forward/k reverse= [P]/[S]

24
Q

V=

A

V= Vmax x [S] / Km + [S]

which is also equal to Kwd x [S]

25
Q

Overall rate depends on rate constants and concentrations. Which equations explain this?

A

Ks->p x [s]
Kp->s x [P]
Usually Ksp . Kps

26
Q

What 2 assumptions do we make about enzyme reactions?

A

[ES] constant

[s] >[E] so [S] is constant

27
Q

Vmax is set by what?

A

Number of enzyme molecules not number of substrate molecules. It is the maximum rate when all is [ES]

28
Q

What is the equation of the Dissociation constant/ affinity for substance Kd?

A

K-1/K1= [E] X[S]/[ES]

29
Q

What does a small Kd mean?

A

high affinity

30
Q

What is Micheals constant?

A

Km= K-1 +Kcat/ K1

31
Q

How do you measure V max ?

A

You cant measure it as its infinity so you find 1/2 V max

32
Q

What are the x and y on Lineweaver-Burk plot?

Whhat doeds intersection of the X and Y axis mean?

A

X= 1/[S] y= 1/V

Y intercept= 1/vmax
X intercept= -1/Km

33
Q

State the equation for V max?

A

Vmax= Kcat x[E]

34
Q

Define Km

What does a low Km mean?

A

Km is [S] when half molecules are ES and its at half maximum rate

Low Km means high affinity for the substrate

35
Q

Kcat catalytic rate constant =

A

number of reactions per second

36
Q

If Kcat/Km > 1x108 the V is limited by what?

A

Diffusion of the substrate to the enzyme not the ezyme itself

BIOL1024 (14 decks)

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