biochem 2 Flashcards

1
Q

Four main features of Enzymes

A

catalysts
efficient
specific
potent

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2
Q

Enzymes are catalysts that increase the reaction rate by reducing __________?

A

activation energy

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3
Q

Examples of enzymes functioning as catalysts

A

Globular proteins
RNA (ribozymes)

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4
Q

At what rate are enzymes faster than a regular reaction

A

10^3 to 10^17

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5
Q

T/F Enzymes have side reactions

A

FALSE

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6
Q

T/F Enzymes do not alter equilibrium

A

TRUE

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7
Q

Enzymes are specific in the sense that they have a limited range of ___________ to produce ______________ products

A

substrates/ specific

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8
Q

Example of the potency of enzymes: carbonic anhydrase produces ________/ sec from bicarbonate

A

1,000,000

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9
Q

Enzymes lower _____________ energy

A

activation

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10
Q

Enzymes have no effect on __________________ of the reaction

A

overall energy change

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11
Q

With an enzyme what increases and what remains the same

A

reaction rate increases
equilibrium constant remains the same

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12
Q

T/F enzymes can catalyze a reaction even when it is unfavorable

A

FALSE

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13
Q

Enzymes act to _______ the activation energy and ________ the transition state

A

lower/ stabilize

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14
Q

when delta G is < 0 the reaction is

A

favorable

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15
Q

when delta G is > 0 the reaction is

A

unfavorable

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16
Q

when delta G = 0 the reaction is

A

at equilibrium

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17
Q

T/F if one reaction is not favorable but has a product that participates in a favorable reaction, the reactions can be linked together to force the original reaction to completion

A

TRUE

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18
Q

Cofactors are

A

non amino acid components that provide a reaction with chemistry that the R group cannot

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19
Q

Co-factors and prosthetic groups must be ___________ is chemically altered

A

regenerated

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20
Q

Cofactors contain

A

2 enzymes
2 reactions

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21
Q

prosthetic groups contain

A

one enzyme (stays attached)
two reactions

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22
Q

True catalysts cannot undergo ______ ________ ________: cofactors must be ____________________

A

permanent chemical change
regenerated

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23
Q

In an enzymatic kinetic graph, the curve levels off when the reaction _______________

A

reaches equilibrium

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24
Q

Km =

A

[S] at Vmax/2

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25
Q

When an enzyme has a high Km it has a __________ affinity for the substrate

A

lower

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26
Q

When an enzyme has a low Km it has a __________ affinity for the substrate

A

high

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27
Q

Why is the M&M equation / analysis helpful

A
  1. Elucidate physiological role of enzymes
  2. Study inhibition action for therapeutics
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28
Q

Where is glucokinase found and at what [] does it work best at

A

liver, B cells of pancreas

[High]

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29
Q

Where is hexokinase found and at what [] does it work best at

A

most tissue including liver
[low]

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30
Q

What is the physiological relevance of gluc/hex

A

the higher Km of gluc. allows the liver to respond to increases in glucose to capture extra glucose when hex is saturated

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31
Q

Km of Hex and Km of Gluc

A

~1 mM and ~7mM

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32
Q

What are isozymes

A

distinct enzymes that catalyze the same biochemical reaction

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33
Q

Isozymes exist within ______, within an. individual at different stages of development, within the same __________ or even same ________

A

species. tissue, cell

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34
Q

Isozymes can have subtle or significant differences in __________

A

primary structure

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35
Q

How can you distinguish isozymes

A

kinetics/ regulatory properties

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36
Q

Creatine Kinase can be found in ______ and _________

A

myocardial infarction and muscle disorders

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37
Q

Lactate Dehydrogenase can be found in both

A

muscle disorders, liver disease

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38
Q

The pharmaceutical actions of drugs are due to their ability to ___________ enzymes specifically

A

inhibit

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39
Q

Alkaline phosphatase can be found in both

A

liver disease and bone disease

40
Q

Inhibitors can be

A

general or specific

41
Q

Examples of general enzyme inhibitors

A

metal ions, organic solvents, acids, alkalis

42
Q

General enzyme inhibitors inactive enzymes _______ and _________ that can still be studied ____________

A

irreversibly and non-spontaneously

kinetically

43
Q

How do general inhibitors work

A

protein denaturation

44
Q

T/F general inhibitors have medical relevance

A

FALSE

45
Q

Specific enzyme inhibitors ________ the substrate of their target enzyme

A

mimic

46
Q

SEI may bind in two ways

A
  1. at the active center but be unable to react any further
  2. Bind and react. to form a product the will not dissociate from the enzyme so that it can no longer participate in anything else
47
Q

T/F enzymes can bind inhibitors with greater affinity than they can bind the substrate

A

TRUE… this is bc the I can mimic the TS.

48
Q

Specific inhibitors can be

A

reversible or irreversible (suicide)

49
Q

Irreversible Inhibitors ___________ bind to active center

A

covalently
ex. nerve gas

50
Q

Competitive inhibitors bind to active center via

A

non covalent bonds

51
Q

T/F High [S] can outcompete I in comp inhib

A

true

52
Q

Non competitive inhibitors bind _____ to the substrate via ________ bonds

A

distal, non-covalent

53
Q

T/F High [S] can outcompete I in non comp inhib

A

FALSE

54
Q

Competitive inhibitors bind to ________, ___________ kM, and changes the ________ intercept

A

E, increases, X

55
Q

Non competitive inhibitors bind to ________, ___________ Vmax, and changes the ________ intercept

A

E and ES, decreases , Y

56
Q

The contact or intrinsic pathway is for trauma ________ of the vascular system that leads to bleeding

A

inside

57
Q

The tissue factor/ extrinsic pathway is for trauma ______ of the vascular system that leads to bleeding. ex. endothelial tissue

A

outside

58
Q

What is an essential cofactor in the blood clotting cascade

A

Vit. K

59
Q

T/F blood clotting is reversible even thought thrombin undergoes irreversible PTM

A

TRUE

60
Q

What degrades fibrin clots

A

plasmin

61
Q

Genetic Coagulation Disorders

A

Hemophilia (A, B and C)
Von Willebrand Disease

62
Q

Hemophilia A and B are _______ recessive and C is ___________

A

x linked recessive, autosomal

63
Q

What factors do all types of Hemophelia use

A

A - factor VIII
B - factor IX
C - factor XI (rare)

64
Q

Von Willebrand Disease is a

A

platelet adhesion defect

65
Q

Acquired Coagulation Disorders (4)

A

Vitamin K deficiency
Liver Disease
Anemia
Low platelet count

66
Q

Autocrine cells target _________
Paracrine cells target _________
Gap Junctions target _________
Endocrine cells target _________

A

itself (immune cells, stem cells, cancer)
cells nearby (cell proliferation, differentiation)
adjacent cells (embryonic, organ tissue)
distant cells (hormonal signaling)

67
Q

GPCR are __________ that are used by cells to convert extracellular signals into intercellular responses

A

intergral membrane proteins

68
Q

GPCR are common

A

drug targets

69
Q

Beta Adrenergic Receptor are made up of

A

catecholamines and epinephrine

70
Q

what does Beta Adrenergic Receptor stimulate

A

nervous system alert

71
Q

4 main functions of the fight or flight response

A

dilate blood vessels
increase heart rate
divert blood to skeletal muscle
energy mobilization

72
Q

Heterotrimeric G(aby) proteins serve what purpose

A

signal transduction and amplification

73
Q

G alpha is active when bound to ________ and inactive when bound to ___________

A

GTP, GDP

74
Q

Ga interacts with 7TM GPCR to do what

A

stimulate GDP –> GTP exchange

75
Q

Intrinsic GTPase activity is the ______ conversion from active to ________ state and is stimulated by ___________

A

slow, inactive, Regulator of G Protein Signaling (RGS)

76
Q

What Ga subfamily stimulates cAMP

A

Gas

77
Q

What Ga subfamily inhibits cAMP

A

Gai

78
Q

What Ga subfamily activates phospholipase

A

Gaq

79
Q

What Ga subfamily activates Rho GTPase

A

Ga12/Ga13

80
Q

___________ is a membrane protein stimulated by Gas

A

Adenylyl Cyclase

81
Q

AC catalyzes the conversion of ATP to

A

3’-5’ cAMP

82
Q

Step 1 of the B adrenergic receptor

A

Ligand (epinephrine) binds to the b-adrenergic receptor

83
Q

Step 2 of the B adrenergic receptor

A

B adrenergic receptor undergoes a conformational change

84
Q

Step 3 of the B adrenergic receptor

A

activates Ga protein by GDP to GTP exchange

85
Q

Step 4 of the B adrenergic receptor

A

Ga-GTP dissociates from Gby

86
Q

Step 5 of the B adrenergic receptor

A

Ga activates adenylyl cyclase

87
Q

Step 6 of the B adrenergic receptor

A

Production of cAMP

88
Q

Step 7 of the B adrenergic receptor

A

Activation of PKA

89
Q

Ways to turn off the B adrenergic receptor

A

feedback inhibition
GTP hydrolysis via RGS
Dissociation of the ligand from the receptor
Desensitization

90
Q

3 types of neurons

A

sensory, motor and interneurons

91
Q

During action potential, neuron to neuron is _____________ gated

A

ligand

92
Q

Action potentials. along the axon are _______________________

A

voltage gated

93
Q

__________________ local anesthetic diffuses. across a membrane. _______________ LA binds to channels

A

deprotonated, protonated

94
Q

pka of LA is

A

~8-9

95
Q

Voltage gated NA+ is important for _________ and __________ function

A

cardiac function, brain function

96
Q

term for the oxidation of the iron in hemoglobin

A

methemoglobin

97
Q
A