CC LEC 2 - Enzymes II Flashcards Preview

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Flashcards in CC LEC 2 - Enzymes II Deck (63):
1


 128,000 Daltons
 Interconversion of lactic acid and
pyruvic acid

LD - Lactate Dehydrogenase

2

Atypical LD
LD-6: ??

alcohol dehydrogenase

3

Atypical LD
Migrates cathodal to LD-5
 Present in patients with
arteriosclerotic cardiovascular failure
 Grave prognosis, signifies impending
death

alcohol dehydrogenase

4

Atypical LD
LD complexed with IgA or IgG, migrates between LD-3 and LD-4

Macro-LD:

5

– to measure LD-1(HHHH) because H-units have great affinity

*a-Hydroxybutyrate dehydrogenase activity

6

Methods for LD
forward reaction
- mixture of phenazine methosulfate
and nitroblue
- tetrazolium reacts with NADH
producing blue purple color
- pH8.3–8.9

1. Wacker method

7

Methods for LD
– reverse
reaction
- NADH is cosubstrate, consumed
during reaction

- pH7.1–7.6

Wroblewski La Due method

8

Methods for LD
- 3 times faster, smaller sample, shorter
reaction time
- Susceptible to substrate exhaustion
and loss of linearity

Wroblewski La Due method

9


 Transfer of amino group between aspartic acid and a-ketoacids

Aspartate Aminotransferase

10

ast coenz

Pyridoxal phosphate is coenzyme

11

ast isoenz
predominant form in serum

Cytoplasmic Isoenzyme –

12

ast isoenz
increased during cell necrosis

Mitochondrial Isoenzyme

13

AST Method
– coupled enzymatic reaction
- Malate dehydrogenase is indicator enzyme
- Decrease in absorbance at 340nm
- Optimal pH 7.3-7.8

Karmen method

14

AST Method
– ketoacids react with 2,4 – DNPH to form ketoacid hydrazines
- Product is intense brown color measured at 505nm

Reitman-Frankel Method

15


- Catalyzes transfer of amino groups from alanine to a-ketoglutarate

Alanine Aminotransferase

16

Liver specific enzyme

Alanine Aminotransferase

17

Not elevated in heart disease unless accompanied with liver disease

Alanine Aminotransferase

18

Tends to be higher and lasts longer than AST in acute inflammatory conditions of the liver

Alanine Aminotransferase

19

Requires Mg2+ and Mn2+ as activators

Alkaline Phosphatase

20

class 3 enz

ALP

21

Hydrolysis of various phosphomonoesters; making it nonspecific in alk

ALP

22

ALP isoenz Increased in B and O secretors

Intestinal ALP

23

Abnormal ALP isoenz

Regan
Nagao

24

Abnormal ALP
Variant of Regan
- Detected in metastatic carcinoma of pleural surfaces and in adenocarcinoma of pancreas and bile duct

nagao

25

Abnormal ALP
Highest in ovarian and gynecologic cancers
- Used for monitoring treatment because it disappears upon successful therapy

regan

26

ALP ISOENZ (3) are most heat stable and resist denaturation at 65C for 30 minutes

Placental, Regan, and Nagao

27

inhibits intestinal (75%) and
placental (80%) ALP ISOENZ

Phenylalanine

28

Nagao is also inhibited by __

L-leucine

29

inactivates bone(90%0 more
than liver(60%) ALP

Urea(2M)

30

Hydrolysis of various phosphomonoesters at acidic pH (5.0)

ACP

31

inhibits prostatic ACP

Tartrate

32

inhibits non-prostatic ACP

Copper

33

__ fastest towards anode; __closer to the cathode

pACP fastest towards anode; eACP closer to the cathode

34

Prostatic cancer stage
Small islands of cancer cells in prostate
Normal Population

1

35

Prostatic cancer stage
Presence of small nodules in prostate
70-90% live for 5 years

2

36

Prostatic cancer stage
Presence of nodes in the prostate and spread around the pelvic area
40-70% live for 5 years

3

37

Prostatic cancer stage
Nodules inside and outside prostate, metastasizing in bones and presence of lymph nodes
15-20% live for 5 years

4

38

First seen in alcohol intake

GGT

39

Transfers gamma glutamyl from gamma glutamyl peptides to Amino Acids, H2O, and other small peptides

GGT

40

serves as the gamma glutamyl donor in most biological systems

Glutathione

41

is present in large extent in smooth ER and is subjected to hepatic microsomal induction

GGT

42

Used as a differentiating source of ALP elevation

GGT

43

Mtd of meas for GGT

Szasz

44

MW of amylase

50 000 - 55 000 daltons

45

Breakdown of starch & glycogen with the products

AMS

46

Requires calcium & chloride ions for
activation

AMS

47

Tx sources of AMS

Acinar cells of pancreas
Salivary glands

48

long, unbranched chain of
glucose molecules, linked by α, 1-4
glycosidic bonds

Amylose

49

branched chain
polysaccharide with α, 1-6 linkages
at the branched points

Amylopectin

50

similar to amylopectin but more highly branched

Glycogen

51

ISOENZ of AMS

- From pancreatic tissue
-

P-type (P1, P2, P3)

52

ISOENZ of AMS
Predominates in urine

P-type (P1, P2, P3)

53

ISOENZ of AMS
markedly elevated in acute
pancreatitis & renal failure

P3

54

ISOENZ of AMS
From salivary gland tissues, fallopian
tubes, lungs

S-type (S1, S2, S3)

55

ISOENZ of AMS
Inhibited by wheat germ lectin

S-type (S1, S2, S3)

56

ISOENZ of AMS
Migrates faster than P-type

S-type (S1, S2, S3)

57

ISOENZ of AMS
Predominates in serum (2/3 of AMS
activity in serum)

S-type (S1, S2, S3)

58

Most commonly observed AMS ISOENZ fractions

P2, S1, S2

59

AMS Method
Measures the disappearance in initial dark blue color of starch-iodine complex
- Fast disappearance = high AMS activity

Amyloclastic/Iodometric Method

60

AMS Method
Reduction test, reference method
- Starch substrate hydrolyzed by AMS
to its constituent carbohydrate molecule that has reducing properties like sugars
- Amount of reducing sugar = AMS activity

Saccharogenic Method

61

AMS Method
Employs a starch substrate with a chromogenic dye that forms an insoluble dye-substrate complex
- With AMS, a smaller soluble fragment of the dye-substrate is formed
- ↑ color intensity of soluble dye- substrate complex = ↑ AMS activity

Chromolytic/Chromogen Labelled Substrate Method (Colorimetric)

62

AMS Method
- Replaced the previous methods in the lab
- Measures the change in absorbance of NAD+ at 340 nm at pH 6.9
- Substrate: maltotetrase/maltopentoase

Coupled Enzyme Reaction/Continuous Monitoring Method

63

# of mg glucose in 30 minutes at 37°C at specific assay conditions

Somogyi units:

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