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Flashcards in Enzymes Deck (42)
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1
Q

Competitive Inhibitor: Vmax ____ while Km ___ (dec, same, inc)

A

Competitive Inhibitor Vmax same, Km increased

2
Q

Noncompetitive inhibitor: Vmax ____ while Km ___ (dec, same, inc)

A

Noncompetitive Inhibitor: Vmax decreased, Km same

3
Q

_____ enzymes bind at sites other than the active site

A

Allosteric enzyme

4
Q

____ enzymes catalyze the same reaction but has different amino acid sequence

A

Isoenzymes (i.e. lactate dehydrogenase, CK)

5
Q

Enzymes ____ (inc, reduces) the Gibbs free energy by ___ (inc, dec) the energy activation

A

Enzymes do not affect the Gibbs free energy by lowering the EA

6
Q

In the Lineweaver-Burk plot, the slope suggests

A

Km/Vmax

7
Q

___ are physically distinct versions of a given enzyme (each of which catalyzes the same reaction)

A

isozymes

8
Q

What is the isozyme of hexokinase

A

glucokinase

9
Q

[Class of Enzyme]

add oxygen

A

Oxidoreductase

1. Oxidase

10
Q

[Class of Enzyme]

add hydrogens

A

Oxidoreductase

1. Reductase

11
Q

[Class of Enzyme]

remove hydrogen

A

Oxidoreductase

1. Dehydrogenase

12
Q

[Class of Enzyme]

move chemical groups from one substrate to another

A

Transferase

13
Q

[Class of Enzyme]

cleave substate bond using water

A

hydrolase

14
Q

[Class of Enzyme]

rearrange substrate

A

Isomerase

15
Q

[Class of Enzyme]

joins substrate forming new bonds

A

synthase

16
Q

[Class of Enzyme]

remove phosphate group

A

phosphatase

17
Q

[Class of Enzyme]

add phosphate groups to substrate

A

phosphorylase and kinase

18
Q

What bond holds the substrate to the active site in the enzyme

A

hydrogen bonds

19
Q

___ are transient, dissociable either to the enzyme or to a substrate; made of vitamins

A

cofactor

20
Q

___ serve as recyclable shuttles that transport many substrates from point A to point B; made of proteins

A

coenzyme

21
Q

____ equation describes how reaction velocity varies with substrate concentration

A

Michaelis-Menten Equation

22
Q

What are the different assumptions in Michaelis-Menten Equation

A
  1. [S] > [E]
  2. [ES] is constant
  3. [P] is low
23
Q

What is the curve of the michaelis-mentin kinetics?

A

curve

24
Q

Once the enzymes are saturated, the velocity of the reaction ___ ( increases, decreases, same)

A

Remains the same

Zero order

25
Q

____ refers to the maximal number of substrate molecules converted to product per unit time

A

maximal velocity

26
Q

___ refers to the substrate concentration at which Vi is half the maximal velocity attainable at a particular concentration of enzyme

A

Michaelis Constant

27
Q

What are the factors that affect the rate of a reaction

A
  1. Substrate concentration
  2. Temperature
  3. pH
28
Q

____ is the reciprocal of the Michaelis-Menten equation

A

Lineweaver burk

29
Q

This graph is used to calculate the Km and Vmax

A

Lineweaver-burk

30
Q

The slope of the lineweaver burk plot is equivalent to

A

slope (m) = Km/Vmax

31
Q

The x-intercept of lineweaver-burk plot refers to the

A

x intercept = -(1/Km)

32
Q

The y-intercept of lineweaver-burk plot refers to the

A

y intercept = (1/Vmax)

33
Q

[Enzyme inhibitor]

shape is similar to the substrate and competes for the binding site

A

competitive

34
Q

[Enzyme inhibitor]

competitive inhibitor can be reversed by?

A

Increasing the [S]

35
Q

[Enzyme inhibitor]

an inhibitor that binds other than the active site

A

non-competitive inhibitor

36
Q

[Enzyme inhibitor]

to reverse non-competitive inhibitors,

A

increase [E]

37
Q

Enzyme activity can be regulated by

A
  1. Change in substrate concentration
  2. Allosteric binding site
  3. Covalent modification
    4, Induction and repression of enzyme synthesis
38
Q

[Regulation of enzyme activity]

___ effectors in the allosteric binding sites when the substrate itself serves as an effector

A

Homotropic effector

39
Q

[Regulation of enzyme activity]

___ effectors in the allosteric binding sites the effector is different from the substrate

A

heterotropic effectors

40
Q

Induction and repression of enzyme synthesis happens in what part of the central dogma?

A

Transcription

41
Q

[Clinical Correlate: Identify the disease]

ceruloplasmin

A

Wilson disease

42
Q

[Clinical Correlate: Identify the disease]

beta-glucocerebrodase

A

Gaucher