C13 Enzymes Flashcards

0
Q

How are enzymes measured?

A

Activity

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1
Q

Enzymes

A

Special group of catalysts that are made up of proteins, speed up reaction

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2
Q

Catalyst

A

substances that lessen the amount of energy required for chemical reactions to occur

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3
Q

Enzyme (structure) Primary

A

amino acid sequence

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4
Q

Enzyme (Structure) Secondary

A

interaction between 2 locations on protein chain

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5
Q

Enzyme (structure) Tertiary

A

folding of chains (3D structure)

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6
Q

Enzyme (structure) Quadernary

A

2 or more separate polypeptide chains

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7
Q

Active site

A

physical location on the enzyme molecule which interacts w/ substrate molecule

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8
Q

Allosteric site

A

non active site, but which may interact w/ other substances to change overall enzyme 3D shape

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9
Q

Isoenzyme

A

structurally diff enzymes (proteins) but which catalyze the same chemical reactions

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10
Q

Cofactor

A

a non protein substance required for normal enzyme activity, maintain enzyme 3D structure, critical for enzyme function

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11
Q

2 types of cofactors?

A

activators (inorganic) & coenzyme (organic)

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12
Q

Holoenzyme

A

Enzyme+coenzyme (prosthetic group)=active enzyme

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13
Q

Proenzyme

A

enzyme-coenzyme=active enzyme

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14
Q

The amount of energy required to stimulate molecules to break their chemical bonds and form new bonds is the ___.

A

activation energy

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15
Q

absolute type enzymes

A

catalyzes only 1 specific substrate

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16
Q

Group type enzymes

A

catalyzes reactions of a particular chemical group

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17
Q

Bond type enzyme

A

catalyzes reactions of particular chemical bonds

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18
Q

Steroisomerism

A

catalyzes reactions of steroisomers

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19
Q

What does the substrate do?

A

saturates enzymes (all enzymes react with excess substrate)

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20
Q

Enzyme activity

A

the rate at which an enzyme catalyzes a chemical reaction

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21
Q

Why is activity measured under Zero Order conditions?

A

because this is where the reaction rate is dependent on the work (activity) of the enzyme

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22
Q

Competitive inhibitors

A

substances that bind at the enzyme’s site, competes with substrate for the active site, addition of additional substrate increases the reaction rate

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23
Q

Non-competitive inhibitors

A

substances that bind at an enzyme’s non-active site, enzyme 3d shape is altered, decreasing enzyme activity, may bind substrate but additional substrate has no effect

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24
Q

uncompetitive inhibitor

A

substances that bind with enzyme-substrate complex

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25
Q

How can enzyme activity be measured?

A

increase of product, decrease of substrate, decrease of co-enzymes, and increase of altered co-enzyme

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26
Q

Fixed-Time Assay

A

substrate concentration is measured at set time intervals to determine enzyme activity

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27
Q

What is a slight delay from the beginning of the reaction to max velocity?

A

lag phase

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28
Q

substrate depletion

A

extreme elevations in enzyme activity may deplete the substrate between measured intervals, causes falsely decreased activity results

30
Q

Multipoint Continuous Monitoring (Kinetic Assay)

A

continuous measurements of substrate-product concentration are recorded by the spectrophotometer of an automated analyzer

31
Q

What is the common unit of enzyme activity?

A

International Unit (IU)

32
Q

1 IU

A

that amount of enzyme that will convert 1 micro-mole of substrate to product per minute under defined conditions

33
Q

NADH

A

Common co-enzyme, absorbs light at 340 NM

34
Q

Why are enzymes used as reagents?

A

to measure other non-enzymes

35
Q

High concentrations of CPK are found in?

A

muscle, cardiac & brain tissues

36
Q

Increased CPK is associated with?

A

damage to the muscle, cardiac, and brain tissues

37
Q

Increased CPK is useful to diagnose?

A

AMIs and skeletal muscle disease (muscular dystrophy)

38
Q

How many isoenzymes does CPK have?

A

3

39
Q

CK-BB

A

Brain

40
Q

CK-MB

A

Cardiac

41
Q

CK-MM

A

Skeletal muscle

42
Q

Because of CK-MBs association with cardiac tissue, increased CPK-MB (>_6% Total CPK activity) is a strong indication of?

A

AMI

43
Q

Lactate dehydrogenase is found in what tissues?

A

skeletal muscle, cardiac muscle, renal tissue, and RBCs

44
Q

Plasma LDH is elevated in what conditions?

A

Liver disease, cancers, AMI, hemolytic diseases

45
Q

How many isoenzymes does LDH have?

A

5

46
Q

LD-1

A

(HHHH) Cardiac, RBCs

47
Q

LD-2

A

(HHHM)

48
Q

LD-3

A

(HHMM) lung, spleen, pancreas

49
Q

LD-4

A

(HMMM) hepatic, skeletal

50
Q

LD-5

A

(MMMM)

51
Q

Aspartate aminotransferase high concentrations are found in?

A

skeletal muscle, cardiac muscle, liver tissue, and lung tissue

52
Q

Alanine aminotransferase has the highest activity in the?

A

liver

53
Q

alkaline phosphate does what?

A

removes phosphates from organic compounds

54
Q

alkaline phosphate has higher concentrations in?

A

bone and liver

55
Q

what group of people have higher ranges of alkaline phosphate?

A

children, because they are still growing

56
Q

Amylase catalyzes breakdown of?

A

starch and glycogen to glucose

57
Q

High concentrations of amylase are found in?

A

pancreas and saliva

58
Q

amylase is filtered into the?

A

urine

59
Q

increased plasma or urine amylase is very sugguestive of?

A

pancreatitis or pacreatic malignancy

60
Q

Gamma glutamyltransferase has high concentrations in the?

A

liver

61
Q

increased plasma GGT is associated with?

A

hepatobiliary disease & alcoholic cirrhosis

62
Q

Lipase hydrolyzes (break down)?

A

fat

63
Q

high concentrations of lipase are found in?

A

pancreas

64
Q

pseudocholinesterase is considered a screening test for exposure to?

A

organophosphate exposure (pesticides)

65
Q

3 step in diagnosing AMI?

A

1-symptoms, physical exam, patient history
2-EKG
3-lab tests

66
Q

Myoglobin is a soluble?

A

heme protein

67
Q

two forms of Troponin?

A

Troponin I and Troponin T

68
Q

Cardiac enzymes, “CAL 911”

A

CPK, AST, LDH

69
Q

What is the “triage” used for?

A

common commercial test package that quantitates the 3 most significant lab markers for AMI: CK-MB, Troponin I, and Myoglobin

70
Q

How are enyzmes measured?

A

At Zero Order